Editorial There is a popular belief in the medical world today that a fatigued individual is more susceptible to disease than a non­ fatigued individual. From the clinical perspective, the effect of exercise on the immune system remains an enigma. That exercise has both immunostimulatory and immunosuppressive effects has been acknowledged for at least the last cen­ tury. Over the last decade in particular, substantial evi­ dence from both laboratory-based investigations into specific aspects of immune functioning and epidemiolog­ ical studies of athletic populations supports this dualis- tic relationship. Athletes, coaches and sports doctors believe, with some justification, that sportspeople are more suscepti­ ble to certain illnesses during intense training and major competition. This is obviously a problem both in terms of their ability to compete, but there are also long term effects on training and health to consider. Somewhat paradoxically, there is the common perception that those who exercise regularly are less susceptible to certain ill­ nesses, such as the common cold. While neither of these observations has been rigor­ ously assessed at an epidemiological level, the evidence would point to a dual effect o f exercise: intense exercise increases illness susceptibility while moderate exercise does the opposite. Nieman2 has depicted this relation­ ship as a ‘J ” shaped curve. Moderate regular exercise can reduce URTI risk to below that of sedentary7 popula­ tion. However, beyond a point specific to each individual, the risk o f infection rises exponentially with an increase in exercise frequency, duration and intensity. The exact mechanisms of this immunosuppression are far from understood. The human immune system is highly complex and precisely ordered. It comprises cells, hormones and soluble immunomodulators that inhabit the bone, marrow, lymphoid tissues and ducts and peripheral circulation. Because o f the number and com­ plexity of its interactions with other body systems, it is almost impossible to delineate, isolate or ascribe a spe­ cific function to any single pathway or mechanism. Moreover, although significant exercise-induced immune alterations can be demonstrated in in vivo assay systems, there are presently no in vitro studies to c o n f i r m that these changes are biologically meaningful. Nevertheless, highly trained and competitive athletes in a variety of sport disciplines, do appear to be at risk of developing an infection, particularly those of the upper respiratory tract (URTIs). Edith Peters, author o f two papers in this edition, was the first South African researcher together with (Eric Bateman) to attempt to quantify rates of post-race illness in ultramarathon run­ ners/’ They confirmed that those athletes who ran the faster times, and trained the highest mileages were more likely than the slower, less well trained runners and the sedentary control subjects to develop URTIs. Subsequent studies on Comrades runners have not entirely supported the ides that it is the more competi­ tive athlete who is more likely to develop post-race URTI. Ms Peters reviews both her own work and that of other exercise immunologists in this publication. Ever since Linus Pauling published his treatise on vit­ amin C and the common cold, this anti-oxidant has enjoyed good press. However, for once there is some fact behind the hype. Peters and her colleagues at Wits have shown that vitamin C supplementation, even more so than the other anti-oxidants (beta-carotene, \itamin E), Oppenheimer and Spaeth, 192 2 1 reduced the incidence of URTIs in ultradistance nmners in the two week period after the Comrades marathon. Interest in the immune response to exercise has arisen for reasons other than those related to sports. One is the possible clinical implications. For example, could exercise play a role in the prevention and treatment of certain illnesses such as cancer and acquired immunod­ eficiency syndrome (AIDS) ? Epidemiological evidence certainly suggests an association between regular physi­ cal activity and a lower incidence of certain cancers. Animal studies have shown exercise training to enhance resistance to experimentally induced tumour growth. Exercise is currently used as an adjunctive therapy to counteract die physically debilitating effects of the illness and treatment, and to improve (lie patients’ physical and psychological state. However, as the immune system plays a fundamental role in the progression of cancer and AIDS, the interactive effect of exercise on the immune system could itself prove to be therapeutically useful. Although there is only one documented case o f H IV transmission as a result of participation in contact sport, athletes engaging in high risk behaviour are at the same risk of infection as non-sports persons. This means that the HIV epidemic will eventually affect physically active people. Dr Martin Schwellnus discusses the effect HIV disease has on the ability to perform exercise, and what role exercise has on disease progression. Despite a lack of epidemiological data from which to calculate the risk of H IV transmission during sports participation, Dr Schwellnus addresses the concerns of sports administra­ tors and participants with regard to this emotive subject. In reading these reviews it may occur to you that in trying to quantify and explain the effect that exercise has on immune functioning, scientists have overlooked a fun­ damental factor: the mind. Although the concept of psy- choneuroimmunology, (the interaction between the neu­ roendocrine and immune systems) is alluded to in the more recent studies, there is as yet no data to back up the theory'. Exercise may be immunostimulatory7 because it reduces negative affective states, increases the release of endogenous opiates and reduces HPAC activation. On the contrary, hard training and competition is immuno­ suppressive, because it serv es as an additional stressor to an already overloaded system. Thus the sportsperson who is most likely to develop a URTI is not the elite athlete w hose entire lifestyle and infrastructure is geared around his or her training. It is the individual who, on top of professional, domestic and social responsibilities, attempts to withstand the same training load as the top class athlete. Dealing with their URTI’s is going to require more than just judicious doses of Vitamin C. References 1. Oppenheimer EH, Spaeth RA. The relation between fatigue and the susceptibility o f rats towards a toxin and an infection. A m J Hygiene 1922;2:51-66. 2. Nieman DC. Exercise, upper respiratory tract infection and the immune system. Med Sci Sports Exer 1994;26:128-139. 3. Peters EM, Bateman ED. Respiratory tract infections: an epi­ demiological survey. S Afr Med J 1983;64:582-584. Dr Lindsay Weight SPORTS MEDICINE MARCH 1996 1 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) • For muscular pain • Effective pain relief • Site specific • Non-staining • Non-greasy Reparil-Gel Relieves m uscular pain. • T ' T . MADAUS PHARMACEUTICALS (PTY) l t d “ f y i * 5-5 Reg. No.: 77/00174/07 2nd Road (cnr 16th Road), Randjespark, Midrand 1685 HI] R epa ril-G e l 100 g contains: Aescin 1,0 g; Diethylamine salicylate 5,0 g. Reg. No. G/13.9/2367 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) m i : s o r m a f r k a x .k h r x a t , o r SPORTS MEDICINE VOLUME 3__________ NUMBER 1_______ MARCH 1996 E d itor Prof TD Noakes Dr MP Schwellnus Editorial Board Dr M E Maolla Dr P de Jager Dr J Skowno Dr P Schwartz P rofR Stretch Dr C de Ridder Prof B C Andrews Dr E \V Dermun Mr R H Farman Prof M Mars Dr C A Noble International Advisory Boar< Lyle J Micheli Associate Clinical Professor i Oithopaedic Surgery Boston, USA Chester R Kyle Research Director, Sports Equipment Research Associi California, USA P rof IIC Wildor Hollmann President des Deutschen Sport iirztebimdes Koln, West Gcnnany Howard J Green Professor, Department of Kinesiology Ontario, Canada George A Brooks Professor, Department of Physical Education California, USA Neil F Gordon Director, Exercise Physiology Texas, USA Edmund R Burke Associate Professor, Biology Department, University of Colorado Colorado. USA Graham N Smith Physiologist Glasgow, Scotland The views expressed in individual articles are the personal view's of the Authors and are not necessarily shared by the Editors, the Advertisers or the Publishers. No articles may be reproduced without the written consent of the Publishers. 1 [>f itcs CONTENTS Editorial L Weight Exercise and the immune system: A review L Weight Exercise and upper respiratory tract infections: A review E M Peters IIIV infection in sport: A review of current issues M P Schwellnus Vit C as effective as combinations of anti-oxidant nutrients in reducing symptoms of upper respiratory tract infection in ultramarathon runners E M Peters et al A social cognitive perspective on promotive and preventive health behaviour in post- apartheid South Africa I Miller 9 16 23 29 THE EDITOR THE SOUTH AFRICAN JOURNAL OF SPORTS MEDICINE PO Box 115, Newlands 7725 PRODUCTION Andrew Thomas PUBLISHING Glenbarr Publishers cc Private Bag X14 Parklaiids 2196 Tel: ( Oi l ) 442-9759 Fax: ( Oi l ) 880-7898 ADVERTISING Marike de Waal/Andrew Thomas REPRODUCTION Output Reproductions PRINTING Horlors Cover sponsored by Ciba-Geigv SPORTS MEDICINE MARCH 1996 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Exercise and the immune system: A review Dr L W eig h t PhD (UCT) Exactly how and why the immune system is challenged by exercise has been the subject of a concerted research effort over the last decade. What has emerged is a highly inconsistent puzzle, because of the extreme com­ plexity of the immune system and the barely quantifi­ able factors that influence it. Further disparity is caused by the large variation in the age, gender and fit­ ness levels of the subjects, the extent or lack o f training, the duration and type o f exercise protocol and the tim ­ ing and frequency o f sampling. H ost defence parame­ ters measured in these studies range from simple determination of leukocyte counts to sophisticated eval­ uations of lymphocyte subsets and functions. Large variations in the reliability of both in vivo and in vit ro assay techniques further compromise die reliability of studies in this field.1 Although diere are few data on the effects of exercise 0 1 1 die immune system as a whole, there is a great deal of information on the influence it has on individual com­ ponents thereof. These studies form the basis o f diis review. Exercise and leukocytes Perhaps the best documented effect of exercise on die host defence system is an acute and immediate leuko- cytosis, the magnitude of which is directly related to the intensity and duration o f work, and inversely pro­ portional to fitness level (for review, see McCarthy and Dale2). The increase in leukocyte number, which can be up to four times the resting level, is predominantly due to increases in neutrophil and, to a lesser extent, lym­ phocyte counts, although monocyte numbers also increase. At die end of exercise lasting up to 3 0 minutes, the leukocyte count usually falls to normal levels within 10- 3 0 minutes. Lymphocyte counts drop 3 0-50% below pre-exercise levels, remaining low for 3 -6 hours. Eosinophils also vacate the blood in large numbers while basophils tire largely unaffected:' After sustained exercise lasting 2 -3 hours, leukocyte counts may still be elevated for up to 2 4 hours. During very prolonged exercise (1 6 -2 4 hours), baseline levels may be reached even before the end o f exercise.4 Moderate intensity7 exercise induces a much less pronounced leukocytosis, lymphocytosis, neutrophilia and lymphocytopenia.'" There appears to be no effect of training on resting leukocyte numbers, with virtually all papers reporting clinically normal values.2 Some investigators have Correspondence: Dr Lindsay Weight Dept Physiology UCT Medical Shool Observatory 7925 Tel: (021) 406-6400 Fax: (021) 477-669 weight@ .physio .uct. ac. za reported that training blunts the leukocytosis o f exer­ cise while others have not.7-8 Leukocyte function and exercise Exercise produces a decrease in neutrophil adherence and bactericidal capacity in conditioned athletes but not untrained subjects. Conversely, phagocytic activity is improved in untrained men but not athletes.9 It is tempting to speculate that the leukocytosis of exercise could protect athletes from bacterial infection. However this is unlikely as the response is so acute and transient and there is no evidence that regular exercise produces long-term adaptation in leukocyte numbers, mobilisation or function. The mechanisms of exercise leukocytosis At rest, more than half o f the body’s mature leukocytes are sequestered in the lungs, liver and spleen. An increase in cardiac output and perfusion of the microvasculature, as well as adrenergic-receptor m edi­ ated changes in the interaction between leukocytes and endothelial cells of the capillaries would mobilise this pool of marginal cells into the blood stream .1011 Epinephrine is a potent beta-adrenergic agonist, and high intensity exercise is known to induce a rapid increase in the density of betas adrenoreceptors.12 Cortisol, while inducing a strong and sustained neu- trophila, also inhibits the entry of lymphocytes into the circulation and facilitates their egress from the blood into other lymphoid compartments.13 Accordingly, this post-exercise leukocytosis is predominantly a neu­ trophilia with a c o n c u r r e n t lymphopenia. Immature leukocytes may also be released from the bone marrow. Hemoconcentration effects are minimal. The mechanisms o f exercise leukocytosis therefore involve a redistribution of existing cells, rather than synt hesis of new cells. McCarthy and Dale’s2 model of exercise leukocytosis is based on the differential activ­ ity of catecholamines and cortisol. Blood concentra­ tions of epinephrine and cortisol rise when exercise intensity exceed 60% of VOa max. Epinephrine effects circulating leukocyte numbers during brief (<1 hr) exer­ cise, while cortisol only comes into play after two to three hours exercise and during recovery. There is a high correlation between serum cortisol .levels and total white cell count post-exercise.1410 In fact, Belgian researchers have proposed that the 3h post-exercise neutrophil-to-lymphocyte ratio is a reliable index of exercise-induced stress in race horses because of its high correlation with post-exercise plasma cortisol con­ centrations.10 Between 3 -4 hours, the total number of leukocytes in the vascular compartment seem s to reach a plateau, representing a temporary homeostatic read­ justment to the prevailing higher plasma cortisol con­ centration.2 Exercise and lymphocytes Resting lymphocyte numbers are usually normal in ath­ letes.2 A lymphocjtosis, proportional to exercise inten­ sity and fitness level occurs during and immediately after exercise of as little as 10 minutes to several hours 4 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) duration. Return to baseline levels follows a similar tiine-sequence to that o f the leukocytes, but lym pho­ cytes numbers may drop to below pre-exercise levels during recovery. The various lymphocyte subsets appear to respond differently to exercise. This is partly explained by their complexity and the techniques used to measure them. What has been consistently demonstrated is that there is a proportionally greater increase in B cells, natural killer (NK) cells and monocytes than in T cells. The T:B ratio decreases, although there does not appear to be a significant change in the T helper:'!' suppressor ratio. Most of these changes are transient and exercise train­ ing has no long-term effect on lymphocyte distribution.17 Cannon18 argues that these acute and transient effects are often attributable to circadian rhythms or hemo- concentration effects. Studies claiming post-exercise ‘ immunosuppression’ rarely include measurements from non-exercising time controls, which may well exhibit a similar pattern o f leukocyte distribution due simply to circadian variation. Effects of exercise on lymphocyte function Determination of the proliferative response (blastogen- esis) of human lymphocytes upon stimulation with mitogens in vitro is a well-established test to evaluate tlie functional capacity o f T lymphocytes. Exhaustive exercise suppresses mitogen-stimulated proliferation of separated mononuclear cells by 50%, while short to moderate exercise has little or no effect.19 The decrease in mitogenic response is probably due to the relative decrease in T cells compared to NK cells in the post­ exercise in vitro assay sample. That is, there is a small­ er percentage of cells that respond to mitogens, due to the differential changes in circulating lymphocyte num­ bers.3 Both cortisol and epinephrine inhibit mitogen- induced lymphocyte proliferation directly and indirect­ ly via their effects on interleukin-2 production." This may explain the reduction in lymphocyte proliferation after high but not moderate intensity exercise. Training may attenuate this suppression.™ Mechanisms oflymphocvte activation Evidence from canine but not human studies is that exercise stimulates lymph flow from skeletal muscle and that this ‘tissue pump’ delivers large numbers of lymphocytes to the circulation, as does an increased perfusion o f the lung.11 Epinephrine promotes exercise- lymphocytosis, while cortisol exerts a limiting effect. Exercise and innate immunity The principle components o f innate immunity are struc­ tural and chemical barriers that limit entry into the host. This first line o f defence is augmented by phago­ cytic cells that kill foreign micro-organisms and release soluble factors that initiate the immune response. Phagocytic functions increase, decrease or remain unchanged, depending on the type, of exercise and the source o f cells.21 Macrophage activity appears to be enhanced by exercise, and there is a suggestion that exercise may enhance macrophage secretion o f tumour necrosis factor (TNF) that inhibits tumour growth. Neutrophil activation and microbicidal activity is either enhanced or michanged by exercise,020 and appears to be lower in trained athletes than non ath­ letes.20 Moderate exercise is associated with a pro­ longed improvement in the killing capacity of neu­ trophils, while exhaustive exercise may have the oppo­ site effect. Both complement and C-reactive protein (CRP) levels tend to be lower in athletes than non-ath­ letes, but increase after prolonged exercise.u-23 While the lower resting acute phase protein concentrations may represent adjustments to chronic training-induced inflammation the implications of these changes for resistance to infection is tin known.'1 Exercise and humoral (anti-body mediated) immunity' The B lymphocytes, when exposed to a specific antigen and/or in co-operation with macrophages, T lympho­ cytes and their soluble products, replicate and mature into plasma cells. These synthesise, and secrete five classes o f antibodies, the immunoglobulins IgG, IgM, IgA, IgG and IgD, which react with, and lead to the destruction o f the antigen. Resistance to infection is due in part to the presence of sufficient levels o f serum and secretory immunoglobulins, especially the antigen- specific IgG and IgA. A pool o f antigen-specific lym­ phocytes forms the basis o f long-term immunity for an individual. Exercise and the Immunoglobulins Most researchers have reported trained athletes to have resting serum immunoglobulin (Ig) levels within the normal reference range and similar to those of sedentary controls.1424 Intense exercise during regular training does not appear to alter serum Ig levels, although some elite athletes may experience low levels during the competitive season.2520 Serum Ig changes following less than 401tm of running are generally minor, but can be depressed for up to two days after completion o f a run longer than 40km . Prolonged endurance exercise has been associated with low sali­ vary IgA levels.2' In contrast, moderate exercise training mav even improve Ig levels.27 Secretary IgA is a glue-like substance o f the mucosal barrier that has anti-body activity against certain virus­ es, bacteria and common allergens. Exercise-induced decreases (within the clinically normal range) in sali­ vary and nasal wash IgA levels have been reported in a variety o f competitive atliletes inducing Nordic skiers 2H, cyclists2”, swimmers30, runners", hockey and squash players and kayakers.32 The intensity of the exercise session and the psychological stress o f competition pro­ foundly affect salivary IgA concentrations.21 These depressed Ig levels are implicated in increased susceptibility to bacterial and viral infections following prolonged exercise. Simon1 argues however tliat exercise-induced alterations in secretory antibod­ ies levels are not likely to be functionally significant, as they are so transient. H e points out that the majority of the 1 in 6 5 0 adults who are entirely deficient in IgA are healthy and do not experience an mcreased incidence of infection. Exercise and Immunoglobulin function hi general, following acute prolonged exercise or sever­ al weeks o f heavy exercise training, in vivo and in vitro antibody production, at least in animal models remains unaltered.2”-33 Whether in vitro Ig synthesis is an accu­ rate reflection o f that occurring in vivo is however debatable. Helper T lymphocytes are essential for B cell differentiation and antibody synthesis. As there is a temporary reduction in the T helper ratio after exer­ cise, the in vitro reduction in Ig synthesis could simply reflect the change in lymphocyte subsets at the time of sampling. SPORTS MEDICINE MARCH 1996 5 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Exercise training may also enhance specific antibody formation in response to immunologic challenge. For example, higher titres of serum Ig specific to injected tetanus toxoid was observed in males completing a 42km marathon compared to controls. This occurred despite a significant decrease in mitogen-stimulated T- cell transformation.7 However the sample size in this experiment was very small (4 runners, 59 controls). Trained mice immunised with injected Salmonella typhi produced markedly higher specific antibody than did the non-exercising controls.34 Mechanisms of exercise-induced immunoglobulin redistribution Plasma volume changes explain most o f the acute exer- cise-related increases in immunoglobulins, together with an increase in Ig-containing ly m p h flow into the vascular compartment/'''’ However, over the long term, baseline Ig production does not appear to be affected by exercise, as evidenced by generally normal resting Ig levels in athletes (Green et al. 1981). There is as yet no explanation for the higher specific antibody response observed after acute exercise and training, although this may represent an enhanced capacity o f the immune system to respond to antigenic challenge.21 Exercise and the cytokines Monocytes and macrophages exert a pervasive influence on host defences by secreting cytokines, which play a central role in initiating and regulating (lie immune response. Principally, these proteins stimulate the cells mediating specific immunity and also induce a wide array of non-specific host defence adaptations.18 There are few published studies on the effects o f exercise on these intracellular messengers. Interleukin-1 (IL-1) is a protein with pleitropic effects, produced by mononuclear cells in response to endotoxin, immune complexes, phagocytosis and other stimuli such as exercise. Interleukin-1 and interleukin- 6 (IL-6) levels and activity has been reported to increase during or in the recovery period after exer­ cise,15-36'37 and to be higher in endurance athletes at rest compared to non-athletes.38 These observations o f exercise-induced increases in IL-1 provide a potentially important link between exer­ cise and host defence mechanisms. Firstly, IL-1 m edi­ ates the acute phase response to infection and inflam­ mation by, among other things, producing a leukocyto­ sis. It is reasonable to speculate that IL-1 exerts a sim ­ ilar effect during exercise. Secondly, IL-1 increases the activity of both B and T lymphocytes. However, whether this is related to changes in immune functioning has not been established. It is possible that the immun- odepressive effects of IL-1 are countered by a decrease in the Th:Ts ratio or other factors that oppose IL-1.30 Interleukin-2 (IL-2) levels in plasma and in vitro IL- 2 production are reduced following brief maximal exer­ cise3”, possibly because of a shift in the Th:Ts ratio and the ability o f the lymphocytes to respond to a immuno­ genic challenge. IL-2 production following prolonged exercise has not been measured.'1 IL-6 release is dependent on IL-1, and it is suggested that there is a co-ordinated release of IL-1, IL-6 and CRP during or after exercise, w7hich may be related to muscle damage and proteolysis, or a general inflammatory response.15 38 Both interferon (IFN) levels and activity increase tran­ siently after one hour moderate exercise.4" Although IFN exhibits anti-viral activity, stimulating cytotoxic cells and inhibiting viral replication the transient and minor fluctuations measured post exercise are not like­ ly to have any biological significance.1 Likewise, tumour necrosis factor (TNF) levels are moderately elevated post-exercise in trained and untrained individuals41, but the functional significance is unknown.21 Levels o f all cytokines studied to date appear to be within clinically normal ranges, even when elevated after exercise.41 It is impossible to determine the effects on immune functioning of an exercise-induced change in a single cytokine. Biological activity of any cytokine depends on a complex network o f interactions, and cytokines may behave differently in vivo compared to in vitro. Exercise and cytotoxic cells Cytotoxic (killing) activity is exhibited by several types o f immune cells, in particular cytotoxic T lymphocytes, natural killer (NK) cells and monocytes/macrophages. The effects of exercise on cytotoxic cells, particularly N K cells, is currently the focus of much research inter­ est. Exercise appears to influence host resistance to both cancer and viral infections, due to its effect on the cytokines involved in resistance to tumour growth and viral infection. Exercise and NK cells N K cells, which comprise about 15% of lymphocytes recognise and kill viral ly infected cells, certain tumour cells and some micro-organisms without prior expo­ sure. They also exhibit spontaneous cytolytic activity. Total N K activity is generally increased during and immediately after brief, prolonged, moderate and intense exercise, and contributes substantially to the overall lymphocytosis (for review see MacKinnon).42 NK cells are selectively recruited into the circulation early in exercise. NK cells have a greater density of betas adrenergic receptors than do other lymphocytes, which explains why circulating levels increase dramatically after high intensity exercise w'hen epinephrine concen­ trations are high.12 Possibly epinephrine, IL-1, IFN, TNF and B-endorphin act synergistically to augment NK activity during exercise. Immediately following exercise the cytotoxic capaci­ ty o f the blood is markedly improved (by 40-100% )w, but the effect is transient. One to two hours after maximal or prolonged exercise, N K activity is low, due to cortisol- mediated decrease in total circulating numbers and the inhibitory influence o f prostaglandins firom activated monocytes and neutrophils.44 Nieman3 argues that per cell, N K cytotoxic activity is actually increased after high but not moderate intensity exercise. There are simply less NK cells around, due to post-exercise egress to peripheral tissues. However, even this is a transito­ ry effect, as baseline N K activity is restored around 6 hours post-exercise.4'1 Resting NK activity in athletes may be slightly elevated compared to non-athletes, but within the normal range.45 Exercise and non-specific host defence mechanisms Anatomical and physiological barriers form the first line o f defence against infection, by preventing penetra­ tion o f micro-organisms firom the environment and the cutaneous and mucosal surfaces of the body into vul­ nerable body tissues. Examples of these non-immuno- logical mechanisms are the skin' and mucous m em ­ branes, the cough and gag reflexes, gastric acidity and intestinal motility. The stress of exercise has a negligible effect on non- 6 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) specific defence mechanisms. Strenuous exercise and sports can result in trauma that disrupts the integrity of the cutaneous barrier to infection, but this is not usual­ ly a clinically important problem. Maceration through perspiration can predispose to annoying superficial fun­ gal infections such as athletes foot.1 Exercise and the acute phase response The acute phase response involves the complement sys­ tem , neutrophils, macrophages, various cytokines and acute phase proteins acting together to clear damaged tissue and initiate repair and regrowth.“ Lymphocytes, neutrophils and macrophages are attracted to the injured muscle cells where they variously phagocytize tissue debris and release soluble products such as cytokines which mediate the inflammatory response ,:l During this process, m acrophages produce prostaglandin Ea which suppresses NK cell activity. There is speculation that when muscle damage is severe, the immune system , partly disabled by prostaglandin is unable to perform its other host- defence duties. That this renders the individual sus­ ceptible to opportunistic infection has yet to be sub­ stantiated by objective measurement.3 The immune response to chronic exercise Several studies have made cross-sectional comparisons o f the immune systems of athletes and non-athletes,2445 or followed immune parameters in sedentary' individu­ als undergoing exercise training.17 Most of these stud­ ies have failed to demonstrate any important effects of regular exercise training 0 11 circulating concentrations of total leukocytes or lymphocytes or their various sub­ populations. Generally, trained athletes have resting serum immunoglobulin levels within the normal refer­ ence range and similar to those of sedentary' controls .27 Longitudinal studies o f collegiate teams over a compet­ itive season show decrements in specific immune para­ meters, which coidd however be simply due to estab­ lished seasonal variations in immune function.50 However, the question o f whether the exercise-induced transitory insults to leukocyte functioning are related to illness susceptibility is still open to speculation.21 Long term leukocyte function is relatively unaffected and mitogen-stimulated lymphocyte proliferation is not altered by exercise training in young adults.47 Suppression o f lymphocyte function has been reported in exhaustively trained athletes48 and neutrophil-killing activity was foimd to be lower in elite athletes com­ pared with untrained controls.22 In contrast, N K cell activity is improved with exercise training.45-43 Nevertheless, results from animal studies consistently show that chronic exertion is related to negative changes in immune functioning/'^2 Towards an integrated model o f the immune response to exercise There are no data on the effects of exercise 0 1 1 the immune system as a whole, and no models that can fully explain the complex interaction o f the physiologi­ cal responses to exercise and how these influence immune function. While individual models may vary' in complexity, all have neuroendocrine factors playing a pivotal role. Psychoneuroimnnmology (PNI) or behavioural immunology is an emerging field that is concerned with the study of the relationships among psychological vari­ ables (such as stressors or affective states such as anx­ iety and depression), the nervous system and the immune system. It is generally accepted that there is a two-way communication between the neuroendocrine and immune systems. Exercise, as a form o f physical stress can be consid­ ered one of the many lifestyle factors such as diet, sleep or work stress that influence the immune system. In addition, exercise training may reduce negative affec­ tive states, increase the release o f endogenous opiates, reduce HPAC activation and enhance immunity.53 Many hormones capable o f immunomodulation are released during exercise, and affected by. training. Smith and Weidemann51 propose that moderate exer­ cise increases the release of immunostimulatory hor­ mones, such as growth hormone, prolactin and B endor­ phin, as well as cytokines such as IL-2 and TNF. Immonosuppressive hormones such as cortisol and cat­ echolamines are generated during intense exercise. The latter would provide some explanation for the anec­ dotal evidence o f increased rates o f infection in elite athletes at times o f intense physical and emotional stress such as occurs during major competitions. Pedersen and Ullum52 propose an ‘open window’ hypothesis. During moderate and severe exercise, immune system functioning is enhanced, but followed by a period o f im num o-depression post-exercise. During this ‘ open window’ period, microbacterial agents may invade the host, and infection be estab­ lished. They suggest that regular moderate exercise may enhance immune functioning, thereby protecting the individual even after a severe exercise bout. Exercise, stress and illness can be viewed as three points on a triangle. Each has independent effects on the immune system, while being mutually interactive.54 For every individual, there is an optimal level o f regu­ lar physical activity' conducive to illness resistance.54 REFERENCES 1. Simon HB. Exercise and immune function. In: Ader R, Cohen F, eds. Psychoneuroimmunology. 2nd ed. New York: Academic Press, 1991. 2. McCarthy DA, Dale MM. The leukocytosis o f exercise: a review and model. Sports Med 1988; 6: 333-363. 3. Nieman DC. Exercise, upper respiratory tract infection, and the immune system. Med Sci Sport Exer 1994; 26: 128-139. 4. Galun E, Burstein R, A ssia E, Tur-Kaspa I, Rosenblum J, Epstein Y. Changes o f white cell count during prolonged exer­ cise. Int J Sports Med 1987; 8: 253-255. 5. Nieman DC, Nehlsen-Cannarella SL, Donohue KM, Douglas BW, Chritton DBW, Haddock BL, Stout RW, Lee JW. The effects o f acute moderate exercise on leukocyte and lympho­ cyte subpopulations. Med Sci Sport Exer 1991; 23: 578-585. 6. Busse W\V, Andersen CL, Ilanson PG, Folts JD. The effect o f exercise on the granulocyte response to isoproterenol in the trained athlete and unconditioned individual. J Allergy Clin Immunol 1980; 65: 358-364. 7. EskolaJ, Ruuslcanen O, Soppi E, Viljanen MK, Jarvinen M, Toivonen H, Kouvalainen K. Effect o f sport stress on lympho­ cyte transformation and antibody formation. Clin Exp Immunol 1978; 32: 339-345. 8. Soppi E, Vatjo P, Eskola J, Laitinen LA. Effect o f strenuous physical stress on circulating lymphocyte number and Junction before and after training. J Clin Lab Immunol 1982; 8: 43-46. 9. Lewicki R, Tchorzewski H, Denys A, Kowalska M, Golinslca M. Effect o f physical exercise on some ;xirameters o f immunity in conditioned sportsmen. Int J Sports Med 1987; 8: 309-314. SPORTS MEDICINE MARCH 1996 7 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) 10. Ahlborg B, Ahlborg G. Exercise leukocytosis with and without beta-adrenergic blockade. A cta Med Scand 1970; 187: 241-246. 11. Muir AL, Cruz A , Martin BA, Thmmasen H, Belzberg A. Hogg JC. Leukocyte kinetics in the human lung: role o f exercise and catecholamines. J Appl Physiol 1984; 57: 711-719. 12. Murray DR, Irwin M, Rearden CA, Ziegler M, Motidsky II. Maisel A S. Sympathetic and immune interactions daring dynamic exercise: mediation via a beta-adrenergic-dependent mechanism. Circulation 1992: 86: 203-213. 13. Cupps TR, Fauci AS. Corticosteroid-mediated immuno-reg- ulation in man. Immunol Rev 1982; 65: 133-155. 14. Nieman DC, Berk LS, Simpson-Westerberg M, Arabatzis K, Youngberg S, Tan SA, Lee JW, Eby WC. Effects of long- endarance running on immune system parameters and lympho­ cyte function in experienced marathoners. Int J Sports Med 1989; 10: 317-323. 15. Weight LM, Alexander D, Jacobs P. Strenuous exercise: analagous to the acute phase response ? Clin Sci 1991; 81: 679- 683. 16. Linden A, A rt T, Am ory II, Massart AM, Burvenich C, Lekeux P. Quantitative huffy coat analysis related to adreno­ cortical function in horses during a three day event competition. Zentralbl Veterinarmed 1991; 38: 376-382. 17. Nehlsen-Cannarella SL, Nieman DC, Balk-Lamberton AJ, Markoff PA, Chritton DBW, Gusewitch G, Lee JW. The effect o f moderate exercise training on the immune response. Med Sci Sport Exer 1991; 23: 64-70. 18. Cannon JG. Exercise and resistance to infection. Med Sci Sport Exer 1993; 74: 973-981. 19. Hoffman-Goetz L, Keir R, Thorne ME, Houston C. Chronic exercise in mice depresses T lymphocyte mitogenesis in vitro. Clin Exp Immunol 1986; 66: 551-557. 20. Hoffman-Goetz L, Thorne RJ, Houston ME. Splenic immune responses following treadmill exercise in man. Can J Physiol Pharmacol 1988; 66: 1415-1419. 21. MacKinnon LII. Exercise and Immunology. Champaign, IL: Human Kinetics Books, 1992. 22. Smith JA, Telford RD, Mason IB, Weidemann MJ. Exercise, training and neutrophil microbicidal activity. Int J Sports Med 1990; 11: 179-187. 23. DuFaux B, Order U, Geyer H, Hollmann W. C-reactive pro­ tein serum concentrations in well-trained athletes. Int J Sport Med 1984; 5: 102-106. 24. Green RL, Kaplan SS, Rabin BS. Stanitski CL, Zdziarski U. Immune function in marathon runners. Ann Allergy 1981; 47: 73-75. 25. Kassil GN, Levando VA, Suzdal’nitskii RS, Pershin BB, K u z’min SN. Neuro-humoral regulation o f immune homeostasis during culaptation to extreme stresses using modern sport as a model. Sport Train Med Rehab 1988; 1: 61-65. 26. Wit B. Immunological response o f regularly trained ath­ letes. Biol Sport 1984; 1: 221-235. 27. Nieman DC, Nehlsen-Cannarella SL. The effects o f acute and chronic exercise on immunoglobulins. Sports Med 1991; 11: 183-201. 28. Tomasi TB, Trudeau FB, Czerwinski D, Erredge S. Immune parameters in athletes before and after strenuous exercise. J Clin Immunol 1982; 2: 173-178. 29. MacKinnon LT, Chick TW, van A s A , Tomasi TB. D ecreased secretory immunoglobulins following intense endurance exercise. Sport Train Med Rehab 1989; 1: 209-218. 30. Tharp GD, Barnes MW. Reduction o f saliva immunoglobu­ lin levels by swim training. E urJ Appl Physiol 1990; 60: 61-64. 31. Muns G, Liesen H, Riedel II, Bergmann K-Ch. Influence o f long-distance running on IgA in nasal secretion and saliva. Deutsche Zeit Fur Sportmed 1989: 40: 63-65. 32. MacKinnon LT, Ginn E, Seymour G. Effects o f exercise dur­ ing sports training and competition on salivary IgA levels. Behaviour and Immunity Proceedings o f the 1990 Australian Behavioural Immunology Group Scientific Meeting. Boca Raton FL: CRC Press, 1992. 33. K east D, Cameron K, Morton A R . Exercise and the immune response. Sports Med 1988; 5: 248-267. 34. Liu YG, Wang SY. The enhancing effect o f exercise on the production o f antibody to Salmonella typhi in mice. Immunol Lett 1986/87 14: 117-120. 35. Wetts CL, Stern JR, Hecht LH. Hematological changes fol­ lowing a marathon race in male and female runners. Eur J Appl Physiol 1982; 48: 41-49. 36. Cannon JG, Evans WJ, Hughes VA, Meredith CN, Dinarello CA. Physiological mechanisms contributing to increased interleukin-1 secretion. J Appl Physiol 1986; 61: 1869-1874. 37. Cannon JG, Kluger MJ. Endogenous pyrogen activity in human plasma after exercise. Science 1983; 220: 617-619. 38. Evans WJ, Meredith CN, Cannon JG, Dinarello CA, Frontera WR, Hughes VA, Jones BH, Knuttgen HG. Metabolic changes following eccentric exercise in trained and untrained men. J Appl Physiol 1986; 61: 1864-1868. 39. Lewicki R, Tchorzewski H, Majewska E, Nowak Z, Baj Z. Effect o f maximal physical exercise on T-lymphocyte subpopula­ tions and on interleukin-1 (IL-1) and interleukin-2 (IL-2) pro­ duction in vitro. Int J Sports Med 1988; 9: 114-117. 40. Viti A , Muscettola M, Paulesu L, Bocci V, Almi A. Effect o f exercise on plasma inteferon levels. J Appl Physiol 1985: 59: 426-428. 41. Espersen GT, Elbaelc A, Aernst E, Toft E, Kaalund S, Jersild C, Grunnet N. Effect o f exercise on cytokines and lymphocyte sub-populations in human peripheral blood. APMIS 1990; 98: 395-400. 42. MacKinnon LT. Exercise and natural killer cells: What is the relationship ? Sports Med 1989; 7: 141-149. 43. MacKinnon LT, Chick TW, van A s A , Tomasi TB. Effects o f prolonged intense exercise on natural killer cell number and function. In Dotson CO, Humphrey JH, eds. Exercise physiology: Current selected research. New York: AMS Press, 1988; vol 3: 77-89. 44. Pedersen BK, Tvede N, Hansen FR, Andersen V, Bendix T, Bendixen G, et cd. Modulation o f natural killer cell activity in peripheral blood by physical exercise. Scand J Immunol 1988; 27: 673-678. 45. Pedersen BK, Tvede N, Chrisensen LD, Klarlund K, Kragbak S, Iialkjaer-Kristensen J. Natural killer cell activity in peripheral blood o f trained and untrained persons. Int J Sports Med 1989; 10: 129-131. 46. Kushner I. The phenomenon o f the acute phase response. Ann NY A cad Sci 1982; 389: 39-48. 47. MacNeil B, Hoffman-Goetz L, Kendall A, Houston AM, Arumugam Y. Lymphocyte proliferation responses after exercise in men: fitness, intensity and duration effects. J Appl Physiol 1991; 70: 179-185. 48. Fry RW, Morton AR, Garcia-Webb P. Biologic response to overload training in endurance sports. Eur J Appl Physiol 1992; 64: 335-344. 49. Nieman DC, Tan SA, Lee WJ, Berk LS. Complement and immunoglobulin levels in athletes and sedentary controls. Int J Sports Med 1989; 10: 124-128. 50. Levi FA, Canon C, Touitou Y, Reinberg A, Mathe G. Seasonal modulation o f the circadian time structure o f circulat­ ing T and natural killer lymphocyte subsets from healthy sub­ jects. J Clin Invest 1988; 81: 407-413. 51. Smith JA, Weidemann MJ. The exercise an immunity para­ dox: a neuroendocrine/ cytokine hypothesis. Med Sci Res 1990; 18:749-753. 52. Pedersen BK, Ullum H. NK cell response to physical activ­ ity: a possible mechanism o f action. Med Sci Sport Exer 1994; 26: 140-146. 53. LaPerriere A , Ironson G, Antoni MH, Schneiderman N, Klima N, Fletcher MA. Exercise and psychoneuroimmunology. Med Sci Sport Exer 1994; 26: 182-190. 54. MacKinnon LT. Current challenges and future expecta­ tions in exercise' immunology: back to the future. Med Sci Sport Exer 1994; 26: 191-194. □ 8 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Exercise and upper respiratory tract infections: A review EM Peters MSc(Med) ABSTRACT Despite equivocal findings in early laboratory and long­ itudinal studies investigating the relationship between exercise and infection risk, recent carefully controlled work appears to point towards a paradoxical response of the host defence and immune systems to endurance exercise; whereas long-term regular training is thought to stimulate these systems, acute exposure to exhaus­ tive endurance exercise has been associated wiitli tran­ sient suppression thereof. Several studies have con­ firmed that athletes are more susceptible to upper res­ piratory tract infection (URTI) symptoms following par­ ticipation in competitive marathon and ultramarathon running events, while others have produced evidence of a protective effect and lower incidences of URTI symp­ tom s following prolonged endurance training pro­ grammes. Nieman (1993) proposes a “J ” shaped rela­ tionship between URTI risk and exercise intensity, whereas Pederson and Ullman (1994) describe an “ open window” period during which the athlete is most vulnerable to infection. How is the athlete best man­ aged (hiring periods o f heavy training and competition? What influences the size o f the “ open window” and URTI risk? These are some o f the questions to be addressed in this paper..... INTRODUCTION Upper Respiratory Tract Infection (URTI) frequently results in inopportune disruption o f the t r a i n i n g pro­ grammes o f serious athletes. In 1 9 7 5 Ryan et al1 reached the conclusion that “upper respiratory illness causes more disability among athletes than all other diseases combined.” This was confirmed by Berglund and Hemmingsson2 who reported that infectious dis­ eases, of which URTI was the most common, was the main medical reason for absence from training in elite skiers monitored over a 12 month period [Figure 1], Regular prolonged exercise, is however, generally recognised as a therapeutic modality providing numer­ ous health benefits; cardiovascular, respiratory and metabolic adaptations have indeed been linked to longevity.'* Many also believe that regular aerobic exer­ cise training improves their resistance to infection and anecdotal reports of fewer colds and URTI infections in well-conditioned athletes abound.4 Correspondence: Edith M Peters, Division of Physical Education, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa. Studies investigating URTI incidence in sportsper- sons reveal a paradoxical response. On the one hand, a high level o f physical conditioning has, in few carefully controlled recent studies, provided evidence o f a lower incidence o f infection symptoms which is possibly asso­ ciated with chronic immunomodulation and an increased resistance to infection.5" ’7 8 On the other hand, overtraining and the combined psycho-physical stress of competitive endurance events and acute bouts of exhaustive endurance exercise have been linked to an increased incidence of URTI symptoms possibly associ­ ated with transient suppression o f host and immune defences.910'1112 O veru se injuries IIIHIII Acu te injuries U R T I S 3 O th er infectious diseases O th e r causes Figure 1: URTI, the main medical reason for absence from training in elite Swedish cross country skiers. Data adapted from Berglund and Hemmingsson.' Nieman13 has graphically depicted the relationship between exercise and URTI incidence in a “J ” shaped model proposing that a moderate and regular exercise load can reduce URTI risk to below that found in seden­ tary population, whereas a high volume and intensity of exercise can increase URTI risk to almost double that found in the sedentary population [Figure 2]. It is thus the purpose of this review to provide a brief overview o f the epidemiological and laboratory evidence which is currently available in support of this dual response and to provide practical guidelines to die ath­ lete, coach and medical practitioner regarding the pro­ phylactic management o f die athlete during periods of increased susceptibility to infection and treatment of the athlete once URTI has set in. CHRONIC TRAINING AND URTI INFECTION RISK A number of longitudinal studies have been designed specifically to consider the chronic effects of repeated bouts of exercise (ie training and racing) on the inci­ dence of URTI. While Linde14 found that on average elite Danish orienteers experienced 2 ,5 infectious episodes (lasting for more than three days) during a one-year period as opposed to 1 ,7 in non-athletic con­ trols and a higher average duration o f symptoms, Health et al1", examining the illness patterns of a cohort of 53 0 male and female runners over a period of 12 SPORTS MEDICINE MARCH 1996 9 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Regular Competition Inactivity training overtraining High - i Moderate - URTI risk \ J Low- i i I i i Low Moderate High Intensity and Volume of Exercise Figure 2 : “J ” Shaped model o f relationship between ranging amounts o f exercise and risk o f URTI. This model suggests that moderate exercise may lower risk o f respiratory infection below that evidenced in sedentary individuals while excessive amounts may increase, the risk. Adapted with permission from Nieman.''' months, found that the average number o f self-reported illness patterns per runner per year was only 1.2 and suggested that chronic high mileage training may pose as great a risk of an infectious episode as racing.1" A rel­ atively low incidence o f URTI symptoms was confirmed by Berglund and Hemmingsson2 who reported an aver­ age o f 1 ,5 and 1 ,8 8 URTI infections per year in groups o f Swedish national team [n=36] and elite college [n = 1 3 6] cross country skiers. T h is study further revealed the incidence of URTI symptoms to be great­ est in the winter months. Osterback and Qyamberg10, surveying the incidence o f respiratory infections in 12yr old children participating in swimming, ice-hockey and gymnastics on a regular basis, however, found no differ­ ences in infection rates when these children were com­ pared to an age-matched control group. Schouten et al17 studied the relationship between the incidence and duration of URTI symptoms (over a 6 month period) and level of sport activity in 9 2 men and 1 0 7 women participating in the Amsterdam Growth and Health study and found statistically negative corre­ lation between the incidence of URTI symptoms and the level of sport activity in the women only. Variance in the findings of these longitudinal studies could well be attributed to disparity in the quality, quantity and frequency of the training completed by the subjects studied. More recent randomized, well-con­ trolled studies on circulating immune system variables and incidence o f URTI symptoms, however, may sup­ port the common belief that a moderate level of physi­ cal training may lower infection risk. Nieman et al(i 7 performed two tightly controlled con­ secutive studies which investigated the effect of endurance training on the incidence of URTI sympto­ matology. Firstly, in a randomised controlled study of 3 6 women (mean age 3 6 years) five 4 5 min sessions, wk 1 of brisk walking at 60% heart-rate reserve resulted in a significant reduction in URTI symptomatology with less than 50% the number o f (lays with symptoms in the walkers than in the sedentary control group over the 15 week period7 [Figure 3]. In a later study URTI sympto­ matology in a group of highly conditioned elderly female subjects who exercised moderately each day for about 1,5 hr | n=12| was compared to a group exercising for 4 0 min 5 times per week [n=14] and control group who only participated in calisthenic exercises [n=16] over a 12 wk period.7 The lowest incidence (8%) o f URTI was reported in the highly-conditioned group who exer­ cised daily, followed by the next lowest incidence in the group which trained at a moderate intensity 5d.w k' over the 12 wk period [Figure 4], A s the highly-condi- tioned distance runners trained more frequently than the lower-distance runners (4 .6 vs 2 .7 sessions per week), frequency of exercise was suggested as a factor which may improve immunosurveillance.7 NUMBER OF SYMPTOM DAYS/INCIDENT J p < 0,05 ____ I (1990) exercise group nonexercise group Figure 3: Mean number o f symptom days per UR TI inci­ dent in exercise and non-exercise groups during a 15 wk study period. Adapted with permission from Nieman et al." ‘ % in c id e n c e of U R T I 3 0 - s y m p to m a to lo g y C h i-s q u a re = 6.3 6 , P = 0 ,0 4 2 ■ ■ ■SSSr B— W a lk in g S e d e n ta ry G ro u p G ro u p Figure 4 : Incidence o f UR TI ( expressed as a percentage o f the group) during a 12 wk study period in highly con­ ditioned, walking and sedentary control groups women (n = 4 2 ). Adapted with permission from Nieman et al.7 10 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Mackinnon and Hooper’ examining secretory IgA response to various exercise conditions, support these find­ ings showing evidence of a cumulative effect of intense daily exercise on local mucosal resistance against pathogenic organisms causing URTI. A group of well trained Australian swimmers presented with significantly higher secretory IgA levels than “stale” , overtrained swim­ mers over a 6 month session, hi contrast, previous studies have shown that salivary IgA levels are depressed in elite well trained athletes'8 "1 and linked these to an increased risk of infection in elite athletes.19 These data may, howev­ er, also point to an endurance training threshold above which URTI risk is increased supporting the “J ” shaped model proposed by Nieman.13 ACUTE EFFECTS OF COMPETITIVE PRO­ LONGED EXERCISE ON URTI RISK A number o f epidemiological surveys performed locally and abroad in the last 12 years suggest that athletes engaging in marathon mid ultramarathon type events are at increased risk for URTI during the two-week post race period The first preliminary investigation was conducted by Peters and Bateman20 at the 1 9 8 2 Two-Oceans Ultramarathon (5 6 km) in Cape Town. A simple epi­ demiological survey on 1 50 successful finishers in this race, and their age-matched non-running controls who resided in the same households, revealed that whereas a mere 15.3% of the non-running controls reported URTI symptoms during the two-week post-race period, thirty-three percent o f the runners completing the race reported URTI symptoms during this same period [Figure 5]. The incidence o f URTI symptoms was high­ est in the fastest runners (p > 0 .0 1 ) and 47% o f those completing the 5 6 km race in less than 4 hrs reported post-race URTI symptoms. Sore throats and nasal symptoms were the most prevalent with more than 80% of the symptoms reported lasting more than 4 days. The finding o f a significantly higher incidence of URTI symptoms among runners during the post-race period was confirmed by Peters in 1 9 8 9 21 when the study was repeated at tlie Milo Korkie Marathon , a 56 km race taking place between Johannesburg and Pretoria [Figure 5|. Nasal symptoms and sore throats were once again the m ost prevalent o f self-reported symptoms during the two-week post-race period and 39% of symptoms lasted more than 7 days. In this stud}7, it was the runners in the low pre-race training status group who had the highest incidence o f post-race infection. To date, an increased incidence o f post-race URTI symptoms has, however, only been reported following events falling into the marathon and ultramarathon cat­ egories. A two-mont h investigation conducted into the pre- and post-event incidence of URTI in a group o f 27 3 participants in 5 ,1 0 and 20 km events in California22 revealed no increase in URTI incidence in the runners during the 7-d post race period when compared to the incidence in the week prior to the race. Although the URTI incidence was highest (33.3% ; p = 0 .0 9 2 ) in run­ ners completing less than 25 km.wk'1 in training, a correlation between pre-race training distance mid fin­ ishing tim es in the race was not found. A s intensity of training is also an important factor in the preparation for these shorter events, weekly training distance may not provide an accurate reflection of pre-race training status in participants in shorter races. RUNNERS CONTROLS (Nonmnners) Figure 5: The incidence o f U RTI symptoms during the post-race fortnight in runners completing 5 6 km Ultramarathon at sea level and moderate altitude and matched sedentary controls. Data from Peters and An investigation into the URTI symptom incidence in 2311 participants before and after the Los Angeles Marathon(LAM)i! revealed an increase in odds ratio of infectious episodes (IE) with an increase in pre-race training distance (km .w k1) (p = 0.04). Reported inci­ dence o f illness was highest in those runners who com­ pleted >97kni,wk l while training in preparation for the event. O f the 1 8 2 8 LAM competitors without infectious episodes (IE) before the race, 12.9% reported IE during the week following LAM vs 2.2% in controls (well trained non-participating runners). These researchers concluded that runners may experience increased odds for IE during heavy training or following a marathon race. More recent nutritional intervention studies per­ formed by Peters et al2425-20 on participants in the 9 0 Ism Comrades Marathon, also confirm these findings of greater incidence o f infection in the runners during the post-race fortnight. O f interest are the observations, that in the case of the 9 0 km ultramarathon, both con­ ditions of “ under-” and “ overtraining” appeared to pre­ dispose to higher post race URTI risk. 242S2li RECENT HYPOTHESES SUPPORTED BY LABORATORY FINDINGS The paradoxical response to exercise A perspective which explains the dual, paradoxical response to exercise is provided by Sm ith and Weiderman27 who propose that while moderate exercise activates the immunostimulatory release of growth hor­ mone, prolactin mid cytokines into the circulation resulting in both neutrophilia and increased neu­ trophilic activity27,28, during very exhaustive prolonged exercise, the immunosuppressive arm of the pituitary- adrenal axis is activated with subsequent release of ACTH and cortisol and suppression o f the activity of the polymorphonuclear neutrophils(PMNs.)27 A further explanation o f the exercise paradox is con­ tained in the theory that initial pro-oxidative effect on PMN function becomes i m m u n o s u p p r e s s i v e as exercise is prolonged and microbicidal reactive oxygen species produced by the PMNs have an auto-oxidative effect reducing the “killing capacity” of the PMNs.20 This was recently confirmed in a study conducted on the nasal SPORTS MEDICINE MARCH 1996 11 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) lavage of runners completing a 20 lan event.'” Although the total number of PMNs rose, percentage active phagocytes and munber o f ingested microorganisms were reduced/*1 Further Smith et al29, comparing neutrophil oxygena- tive activity in elite trained Australian cyclists to that in untrained subjects, showed that endurance training decreases the auto-oxidative phagocytic activity in the PMNs. Further evidence of reduced oxidative act ivity in trained individuals has most recently been reported by Pyne et al31 who in a study conducted on elite swimmers over a 6 month period showed that (i) elite swimmers undertaking intensive training have a significantly lower neutrophil oxidative activity at rest than do age- and sex-matched sedentary individuals and (ii) aspects o f oxidative activity in swimmers are further sup­ pressed during periods of strenuous training. In this study the extent o f the suppression did, however, not appeal- to be of clinical significance as no significant dif­ ference was reported in URTI incidence between swim­ mers and sedentary individuals.31 Increased post-event susceptibility to URTI Consistent evidence exists of increased post-race URTI symptomo] ology in runners competing intensively in events o f the marathon-ultramarathon category. Many existing laboratory findings also appear to lend support to these epidemiological findings and, in particular, the recent hypothesis of Pederson and Ullman32 that the during first few hours following strenuous exertion, an “ open window” exists. This Danish group contend that previously reported reversal of the exercise-induced increment in leucocyte number,33-34'35-3G'37 commonly referred to as a “biphasic” response”, contributes, together with the post-exercise decrease in NK cell number3238, complement39 and mucosal IgA levels’’, to transient immunosuppression during this open window period [Figure 6]. Pederson and Ullman suggest that, at this time, the athlete is most vulnerable to infection; microbacterial agents can invade the host and infec­ tions are easily established [Figure 6]. According to the findings of Nieman91335 the phase o f transitory immuno­ suppression lasts between 6 and 2 0 hours post-exer­ cise.35 Figure 6: The open-window hypothesis o f Pederson and Ullman:12 Severe exercise is followed by a period o f tran­ sitory immunodepression during which the athlete pos­ sesses an increased susceptibility to infection. Adapted from Pederson and Ullman.12 MANAGEMENT OF THE ATHLETE ... PRACTI­ CAL GUIDELINES FOR ATHLETE, COACH AND CLINICIAN Advice for the athlete in possession o f URTI symptoms The effects o f systemic infections oil impairing muscle and circulator}^ function and reducing physical work capacity are well established.™ Nieman9 thus proposes that if an athlete experiences sudden and unexpected deterioration in performance during training or compe­ tition, viral infection should be suspected. W hile Fitzgerald41 warns that exercising during the incubation period may worsen the illness, participation during the presence of systemic infection is generally regarded as counterproductive resulting in both poor performance and a prolongation o f the recovery period.12 In view of the additional risk o f myocarditis, a recognized, although rare cause o f death in exercising individuals possessing influenza virus42, athletes‘with constitution­ al symptoms of infection should not be expected to par­ ticipate in competition; even strenuous training should be discouraged in the presence of fever, myalgia, swollen lymph glands, extreme tiredness or other symptoms which are suggestive o f systemic infection.12 Two to four weeks should probably be allowed before resuming hard training.9 However, in the case o f mild common cold with no constitutional symptoms, complete interruption of exercise schedules is not generally required and mild exercise does not appear to be contraindicated. In fact, som e individuals report relief o f symptoms, probably, according to Sim on12, because o f the increased mucous flow associated with exercise. Sim on12 recom m ends gentle stretching sessions, permitting ordinary daily activities to the limit of tolerance with a programme of graded aerobic exercise and reassurance on resumption o f training. M ost clinical authorities in this area12*' recommend that regular training may be safely resumed a few days after the resolution of symptoms and warn that adm o­ nitions for prolonged bed rest are responsible for deconditioning which can give rise to protracted fatigue even after infection has subsided. Eichner43 recommends a “neck-check” . H e suggests that if the athlete has “below-tlie-neck” symptoms such as aching muscles, a hacking cough, vomiting or diarrhoea, all training should be halted; in the case o f “ above-the-neck” symptoms including stuffy or runny nose, sneezing or a scratchy throat, he recommends that at hletes “ go ahead and plough cautiously” through their scheduled work-out. “ If, after 10 minutes, your head is clear and you feel better, you can speed up and finish your workout. If, instead, your head pounds and you feel like you are running through water, stop, go home and rest!” , advises Eichner. In terms o f the use o f cold remedies, caution is advised. Most South Africans recall the unfortunate controversy surrounding the stripping of the title from Comrades gold-medallist, Chari Matheus, in 1992. M ost cold rem edies do contain sympathominetric agents which are on the list o f banned substances. Disqualification o f athletes from high-level competitive events is thus often a possibility when cold remedies are being used. 12 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) The advisability athletes using anti-biotics when con­ tracting an apparently severe local bacterial infection, is an area which does not yet appear to have been investi­ gated. Whereas this would no doubt assist in early com­ bating o f the infectious microorganisms and prevent extension of nasal infections into the lower respiratory tract and ears, hence resulting in a shortening o f the lay-off period, anecdotal reports o f transitory periods of general weakness and lethargy resulting from anti-biot­ ic ingestion, do abound. A t this stage it would appear that athlete and clinician would need to weigh up the advantages of a greater possibility o f overcoming the infection sooner against the transitory period o f reduced performance which may result from the intake o f anti-biotics. A s large individual differences in response to administration o f anti-biotics may also exist, well controlled clinical studies are needed in this area. Prophylactic measures (1) Avoidance o f exposure to infectious agents Since endurance exercise is associated with muscle cell damage and an increased intake o f potential pathogens through increased ventilator}7 flow rates, Weidnerw sug­ gests that particularly during the winter months, expo­ sure to the cold virus in crowded dormitories, class­ rooms, and gymnasiums perhaps accounts for the high incidence o f colds during the cooler months. He further recommends “careful handwashing, avoidance o f skin- to-skin contact or contact with contaminated tissues, sporting equipment, and appliances.” (2) Immunization o f athletes A t present, the evidence regarding effectiveness of the immunization of athletes against influenza appears to be anecdotal and variant; successful in some individu­ als, but bringing on flulike symptoms in others. Melman43 reports the use o f the anti-viral agents aman­ tadine hydrochloride and rimantadine hydrochloride which are both effective against influenza A as a pro­ phylactic measure among the group when the first ath­ letes develop flulike symptoms. This may be particular­ ly helpful for athletes who play winter sports as close contact among teammates can result in rapid spread of influenza and thus disrupt the whole season.13 (3) Enhanced intake o f Vitamin C Recent placebo-controlled studies perform ed on Com rades athletes'"'20 have provided evidence of decreased incidences o f URTI symptoms dining the post-race “open window” period following three weeks o f supplementation with Vitamin C, and Beta Carotene- Vitamin C and E combinations. In both studies a total daily intake o f approx l g Vit C a day resulted in a sig­ nificantly lower incidence o f URTI symptoms during the t wo-week post-race period w7hen compared to the inci­ dence in runners receiving placebo’s. We hypothesised that phagocytic production o f reactive oxygen species (ROS) during prolonged exercise suppressed neu- tophilic function and that the anti-oxidant properties of Vitamin C contributed to a neutralization o f the ROS, lifting the transient post-race immunosuppression. Although these hypotheses are supported by laboratory work on patients possessing auto-immune respiratory disorders and a link between plasma Vitamin C levels and neutrophilic activity has been established, it does require further verification on athletes participating in ultradistance events. A t this stage, anecdotal reports of many coaches w7ho find it o f benefit to increase Vitamin C intake o f athletes in heavy training, particularly dur­ ing the whiter months, do abound. A s Vitamin C is w7ater-soluble and no negative side-effects have been documented at these levels, an enhanced Vitamin C intake is not contra-indicated as a prophylactic mea­ sure. (4) Training progression Careful attention should be paid by coaches to slow7 pro­ gression in training intensity and duration and the avoidance o f overtrained conditions and the resultant immunocompromising effects thereof.*’ Coaches report that more frequent, less intense sessions, have been shown to be more effective in building resistance to infection than very heavy training sessions at less fre­ quent intervals. A s evidence in this field is largely anec­ dotal, w7ell controlled studies are, how7ever, required. CONCLUSION Although many findings in this field remain inconclu­ sive, current evidence would appear to suggest that w7hile exercise provides favourable physical and psycho­ logical stress, a therapeutic and immunostimulatory effect is obtained. It would seem that once exercise is too intense, frequent and/or long in dmation, particu­ larly w7hen coupled w7ith exposure to pathogenic microorganisms, the favourable stress situation devel­ ops into one of distress and a concomitant increment in susceptibility to infections, results. Greater aw7areness o f the predisposing factors can assist coach, athlete and clinician in lessening the onslaught and reducing the length o f the lay-off period when the athlete is exposed to a high bacteriological/virological count. REFERENCES: 1. Ryan AJ, Dnlrymple B, Dull B, Kaden U'.S, Lerman SJ. Round table, respiratory tract infections in sports. Phijs Sport Med 1975;3:29-42, 1975. 2. Berglund B, Hemmingsson P: Infectious disease in elite cross country skiers: a one-year incidence study. Clin Sports Med 1990;2:19-23. 3. Paffenberger RS, Hyde RT, Wing AL, Hsieh CC: Physical Activity, all cause mortality and longevity o f college alumni. New Engl J Med 1986;314:65-613. 4. Nash IIL. Can exercise make us immune to disease? Phys Sports Med 1986;14:25-253. 5. MacKinnon LT, Hooper S. Mucosal (Secretory) Immune System responses to exercise o f varying intensity and during overtraining. Int J Sports Med 1994;15:S179-183. 6. Nieman DC, Nehlsen-Cannarella SL, Markoff PA, Balk- Lamherton H, Yang II, Chritton DBW, Lee JW, Arabatzis K. The effects of moderate exercise training on natural killer cells and upper respiratory tract infections. Int J Sports Med 1990;11:467-473. 7. Nieman DC, Henson DA, Gusewitch G, Warren BJ, Dotson RC, Butterworth DE, Nelson-Cannarella SA. Physical activity and immune function in elderly women. Med Sc Sports Exerc 1993;25:823-831. SPORTS MEDICINE MARCH 1996 13 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) 8. Crist DM. MacKinnon LT, Thompson RF. Alterbom HA, Egan PA. Physical Exercise increases cellular mediated cytotox­ icity in elderly women. Gerontology 1989;35:66-71. 9. Nieman DC. Exercise. Infection and Immunity. Int J Sports Med 15:1994;S131-140. 10. Shephard RJ. Shek PN. A thletic Competition and Susceptibility to Infection. Clin J Sports Med 1993:3:75-77. 11. Shephard RJ. Verde TJ, Thomas SO, Shek P. Physical A ctivity and the Immune System. Can J Sports Sci 1991:16:163-185. 12. Simon HB. Exercise and Infection. Phys Sportsmed 1987;15:135-141. 13. Nieman DC. Exercise, upper respiratory infections and the immune system. Med Sci Sports Exerc 1994:26:128-139. 14. Linde F. Running and Upper respiratory Tract Infections. Scand J Sport Sc 1987;20-23. 15. Heath G IV’ Ford ES, Craven TE. Macera CA. Jackson KL. Pate RR : Exercise and the incidence o f upper respiratory trad Infections. Med Sci Sports Exerc 23:152-157. 16. Osterback L. Qvarnberg Y : A Prospective Study o f Respiratory Infections in 12-years-old children actively engaged in Sports. Acta Physiol Scand 1987:76:944-949. 17. Schouten IK7. Vershuur P. Kemper IICG : Habitual physi­ cal activity, strenuous exercise, and salivary immunoglobin A levels in young adults : The Amsterdam Growth and Health study. Ini J Sports Med 1988;9:289-293. 18. Tomasi TB, Trudeau FB, Czerwinski D, Erredge S : Immune parameters in athletes before and after strenuous exercise. J. Clin Immunol 1982:2:173-178. 19. Von Weiss M. Fuhrmansky J. Lulay R. Weiker II : HaufigkeiL unci Ursache von Immunoglohinmangel bei Sportlern. Dtsch 'A. Sportsmeclizin 1985:36:146-153. 20. Peters EM : Altitude fails to increase susceptibility o f ultra- marathon runners to infections. S Afr J Sp Med 1990;5: 4-8. 21. Peters EM, Bateman ED : Ultramarathon running and upper respiratory tract infections. S Afr Med J 1983;64:582- 584. 22. Nieman DC, Johansen LM, Lee J W : Infectious episodes in runners before and after a road race. J Sports Med Phys Fitness 1989:29:289-296. 23. Nieman DC, Johansen LM. Lee JW. Arahatzis K : Infectious episodes in runners before and after the Los Angeles Marathon. 1990: J Sports Med Phys Fitness 30: 316-328. 24. Peters EM. Cambell A, Pawley L : Vitamin A fails to increase resistance to upper respiratory infection in distance runners. 1992:S Afr J Sports Med 7: 3-7. 25. Peters EM. Goet /sche JM. Grobbelaar B, Noakes TD : Vitamin C supplementation reduces the incidence o f post-race symptoms o f upper respiratory trad infection in ultradistance runners. Am J Cl Nutr 1993:57:170-174. 26. Peters EM, GoetzscheJM, Joseph LE, Noakes TD: Anti-oxi­ dant Nutrient Supplementation and Symptoms o f Upper Respiratory Tract Infections in Endurance Runners (A b stra ct). Med Sci Sports Exerc 1994:26:S218. 27. Smith JW. Weiderman MJ : The exercise and immunity paradox: A neuroendocrine/cytokine hypothesis. Medical Science Research 1990:18:749-753. 28. Anderson R. The activated neutrophil - formidable forces unleashed. S Afr Med J 1995;85:124-127. 29. Smith J. Telford Rl). Mason IB, Weiderman MJ. Exercise, training and neutrophil Microbicidal activity. Int J Sports Med 1990:11:179-187. 30. Muns G : Effect o f Long Distance Running on Polymorphonuclear Neutrophil Function o f the Upper Airways. 1993: Int J Sports Med. 15: 96-99. 31. Pyne DA. Baker MS, Flicker PA, McDonald 11/1, Telford RD. Weiderman MJ : Effects o f an intensive I2-ivk training pro­ gram hi/ elite swimmers on neutrophil oxidative activity. Med Sci Sports Exerc 1995:27(4) -.536-542. 32. Pederson BK, Ullman H : NK Response to Physical Activity: possible mechanisms o f action. Med Sci Sports Exerc 1994;26:140-146. 33. Berk LS. Nieman DC. Youngberg M’S. Arabatzis K, Simpson-Westerberg, Tan S/1. Eby WC : The effect o f long endurance running on natural killer cells in marathoners. Med Sci Sports Exerc 1990:21:207-202. 34. MacArthy DA, Dale MM : The Leucocytosis o f Exercise. Sports Med 1988:6:333-363. 35. Nieman I)C, Berk LS. Simpson-Westerberg M. Arabatzis K, Youngberg S. Tan S/4. Lc'e JW. Eby WC : Effects o f Long- Endurance Running on Immune System Parameters and Lymphocyte in Experienced Marathoners. Int J Sports Med 1989:10:317-323. 36. Gabriel HL, Schwartz P, Kindermann W. Differential mobil­ isation o f leukocyte and lymphocyte subpopulations into the cir­ culation during endurance exercise. Eur J Apppl Physiol 1992:65:529-534. 37. Nelson-Cannarella SL. Nieman DC, Balk-Lumberton AJ, Markoff PA, Chritton DB. Gusewilch G. Lee JW : The effects o f moderate exercise training on immune response. Med Sci Sports Exerc 1991:23:04-70. 38. MacKinnon LT : Exercise and natural Killer Cells. What is the relationship? Sports Med 7:141-149,1989. 39. Nieman DC. Tan S/4. Lee JW, Berk LS : Complement and immunoglobin levels in athletes and sedentary controls. Int J Sports Med 1980:10:124-128. 40. Friman G, Wright JE, Ilback NG. Does fever or myalgia indicate reduced physical performance capacity in viral infec­ tions? Acta Med Scand 1985:217:353-361. 41. Fitzgerald L : Overtraining increases the susceptibility to infection. Int J Sports Med 1991:12.S5-S8. 42. Phillips M, Robinowitz M, Iliggins JR, et a l : Sudden car­ diac death in Air Force recruits. A 20-year review. JAMA 1986:256:2693-2696. 43. Eichner RE : Infection, immunity and exercise. What to tell patients? Phys Sports Med 1993:21:125-135. 44. Weidner TO : Reporting behaviours and activity levels o f intercollegiate athletes with an URL. Med Sci S/xirls Exerc 1994:26:22-26. 45. Mellman Ml), Schelkun PII : Immunization Strategies for active Adults. Phys Spoils Med 1994:22:91-102. u SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) GLENBARR PECIALIST PUBLICATION FREE Doctors Contact: GLENBARR PUBLISHERS 25 Bompas Road, Dunkeld West, 2196. Tel: (011) 442-9759 Fax: (011) 880-7898 To Medical R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) HIV infection in sport: A review of current issues M. P. Schwellnus (MBBCh, MSc(Med) Sports Science, M D, FACSM) ABSTRACT Regular participation in physical activity is well recog­ nized as an important preventative health measure. In contrast, in the last decade, human immunodeficiency virus (HIV) infection has become a major global public health threat. The impact o f H IV infection is likely to have a major effect on the South African population as a whole, including the sporting population. In this arti­ cle issues relating to H IV infection and participation in physical activity are reviewed. These issues include the risk of H IV transmission during sports participation, the effects of H IV infection 0 1 1 exercise performance and the effects of regular exercise on the clinical out­ come of H IV infection. In addition practical guidelines are offered to i) decrease the risk of H IV transmission during spoils participation, and ii) to ensure safe par­ ticipation in physical activity for patients with docu­ mented H IV disease. INTRODUCTION The health benefits o f regular participation in p h y s ic a l activity are well established (Astrand 1992). Regular physical exercise is an essential component of a healthy lifestyle. Public awareness about the health benefits of regular exercise has resulted in an increase in the num­ ber of participants in all types o f sport (contact and non­ contact sport). It is estimated that more than 4.3% of the South African population regularly participate in sport (HSRC 1982). Recent surveys indicate that the m ost popular sport in South Africa is soccer followed in popularity by racquet ball sports, athletics and tennis (COSAS, 1990). In contrast to positive lifestyle changes such as regular exercise, the H IV pandemic has in recent years become a major global as well as South African public health threat (Ijsselmuiden et al, 1988a, Schall 1990, Schoub et al 1990). The acquired immune deficiency syndrome (AIDS) was first recognized as a clinical entity by the Centers for Disease Control (CDC) in 1981 with the description o f 5 cases o f Pneumocystis carinii infection and 26 cases Correspondence: Dr. M. P Schwellnus Sports Medicine MRC/UCT Bioenergetics of Exercise Research Unit Department of Physiology University of Cape Town Medical School P O Box 115 Newlands Cape Town 7725 Rep. of South Africa Tel: (021) 686 7330 Fax: (021) 686 7530 o f Kaposi’s sarcoma in homosexual males (M MWR 1981a, M M W R 1981b). The first cases o f AID S in South Africa were described one year iater (Ras et af 1982). The transmission (Friediand et al 1987, Lifson 1988), clinical features (Sher 1 988), epidemiology (Moodie 1988a), serology (Moodie 1988b), and mortality associ­ ated with human immunodeficiency virus (HIV) infec­ tion have been well described. Although there is con­ siderable debate on the precise impact of the H IV epi­ demic on the South African society (Schall 1 990), it seem s certain this disease will have a considerable effect on the health o f the South African population, including the sporting population. The association bet ween physical activity and HTV infection can there­ fore not be ignored. Specific issues that need to be con­ sidered are the risk of H IV transmission (luring sports participation, the effect of H IV infection on sports per­ formance and the effects of regular physical act ivity on the clinical outcome of H IV infection. The aim o f this article is i) to review' the current: knowledge on the risk o f H IV transmission during sports participation, ii) to establish guidelines to reduce the possible risk o f HIV transmission during sports participation, iii) to review7 the effects o f H IV infection 0 1 1 exercise performance and iv) to review the effects of regular physical activity on the outcome of H IV infection. The risk o f H IV transmission during sports participation Since its discovery in 1983, the human immunodefi­ ciency virus (HIV) has been isolated in blood, semen, cervical secretions, lymphocytes, serum, plasma, cere­ brospinal fluid, tears, saliva, urine, breast-milk and alvoelar fluid of infected subjects (Friediand et al 1987, Ziegler et al 1986). However, the transmission o f the virus from one individual to another has only been linked directly to blood, semen and cervical secretions with likely transmission occurring through breast-feed­ ing (Lifson 1988). The primary routes o f transmission are therefore by sexual contact with an infected person, parenteral exposure to infected blood or blood products and perinatally from an infected mot her to her child. Prior to 1 989, there has been 11 0 documentation of H IV infection occurring as a result of participation in sports. How7ever, the theoretical possibility7 of H IV transmission through open bleeding wounds in contact sports has been recognized by sports physicians (Alcena 1988, Loveday 1989). The first case of possible H IV transmission as a result of sports participation w7as pub­ lished in 1 9 9 0 (Torre et al 1990). This involved an Italian soccer player in whom H IV seroconversion w7as documented weeks after a traumatic incident during a soccer match. During the soccer match the player col­ lided with another player w7ho w7as later documented as being H IV seropositive. Both players sustained open bleeding w7ounds resulting in possible mixing of blood. There w7as no indication that the player may have been infected through any other route of HIV transmission. The authors concluded that this was the first case of 16 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) H IV transmission which occurred directly as a result of sports participation (Torre et al 1990). Although this case report has been criticized on epidemiological grotmds (Goldsmith 1 992), it nevertheless has clear implications for the risk o f H IV transmission during sports participation. In particular, those sportspeople that participate in contact sports such as boxing, wrestling, rugby and soccer are potentially at risk. It must be emphasized that to date no cases of HIV transmission have been recorded in either the sporting or the non-sporting population through contact with saliva, social contact or sharing facilities such as living space, toilets, bathrooms, eating and cooking facilities (Loveday 1989). It must also be borne in.mind that the risk of H IV infection in sportspeople is the same as that in the general population if there is a history o f engag­ ing in well established high risk behaviors for H IV transmission (Table 1). Table 1 : High risk behaviour for H I V transmission - Anal sexual intercourse with or without the use of a condom - Sexual intercourse wit h multiple partners or with one person who has sexual intercourse with multi­ ple partners (eg. prostitutes) Vaginal or anal sexual intercourse with someone who uses intravenous drugs or engages in anal sex­ ual intercourse - The sharing o f needles, razors, toothbrushes or any instrument that may cause bleeding (including mouthguards) - Sexual intercourse with an H IV infected person - especially if a condom is not used - The use o f drugs or excessive alcohol may result in participation in the above mentioned behavior patterns Although there is documentation o f only' a single pos­ sible case o f H IV disease as a result o f sports participa­ tion in contact sports, there is a need to establish clear guidelines for the prevention o f HTV transmission din ­ ing sports participation. As early as 1 9 8 9 the International Sports M edicine Federation (FIM S), together with the World Health Organization, pub­ lished guidelines for the prevention of H IV transmis­ sion during contact sport (WHO position statement 1989). Subsequently, other organizations such as the Australian Sports Medicine Federation (Sheridan, 1 992), the American Academy o f Pediatrics (American Academy o f Pediatrics, 1 9 91), and m ost recently, the National Football League in the USA (Brown et al 1994) have published similar guidelines. In South Africa, to date only the South African Football Medical Association (SAFMA) have published an official posi­ tion statement on H IV disease in sport. The question that is foremost in the minds of sports administrators and participants, is what is the risk of H IV transmission in sport. In answer to this, tliere are no epidemiological data available to date to calculate the risk of H IV transmission during sports participa­ tion. At best, a theoretical risk o f transmission in a sport can be calculated by7 considering the following variables (Sheridan, 1992): - the estimated carrier rate of H IV in the sports par- - the estimated chance o f an open bleeding wound in a sports participant (Incidence o f open bleeding woimds) - the estimated chance of two players with open bleed­ ing woiuids making contact that could result in blood to abrasion or blood to mucous membrane exposure (incidence of physical contact between two partic­ ipants) - (lie estimated chance o f transmission of the virus when infected blood makes contact with an open bleeding wound (estimated to be 0.3-0.5% which is similar to that calculated for a needlestick injury) I f all the above data are available for a particular sport, the estimated risk of H IV transmission can be calculat­ ed (Table 2). At present, accurate data are only avail­ able for one sport, American football (Calabrese 1993). In American football the risk o f H IV transmission in a game has been calculated as 0 .0 0 0 0 0 0 0 1 0 4 . This can be translated to approximately one player becoming infect­ ed per 10 0 million games. Clearly, this is a very low risk and is probably the reason why there is no widespread documentation o f HIV infection in American football players. Table 2: Calculation o f the theoretical risk of H IV transmission in sport Risk = Seroprevalence o f H IV (%) X Risk of open bleeding wound (%) X Risk o f contact with a bleeding player (%) X 0 .0 3 * *: Estimated to be similar to the risk o f seroconver­ sion after a needlestick injury ticipants (% participants that are H IV positive) However, it must be pointed out that the seropreva­ lence in American football players was estimated to be 0.5%, and that both the risk o f an open bleeding wound (0.9%) and the risk of contact between players (7.7%) were low. These estimates will differ between different populations (higher seroprevalence) and sports (higher risks o f bleeding and player contact). For instance, in a boxing light of 12 rounds, the risk o f an open bleeding wound is approximately 33%, and the risk of contact is probably 100%. The risk o f seroconversion after contact between two boxers may also be higher than that o f a needlestick injury for at least two reasons. Blood may be forced into the wound by the nature o f the blow, and contact may be repetitive. Finally, if the seroprevalence o f H IV in boxers is high, the risk of transmission in box- ing may be much higher than that reported for American Football. There is thus a need to obtain accu­ rate research data on the incidence and nature o f open bleeding wound injuries as well as the risk o f contact between play7ers if more accurate assessments on die risk of H IV transmission during sports are to be made. Despite the lack of accurate scientific data, the pre­ vention of H IV disease in sportspeople has to be addressed by establishing clear guidelines for sports participants, administrators and medical personnel involved in sport. A number of practical recommenda­ tions can be made to decrease d ie risk o f H IV trans­ mission in sport. These are summarized in Table 3. SPORTS MEDICINE MARCH 1996 17 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Table 3: Guidelines for the prevention o f HIV transmission in sports a. General guidelines: T he following general guidelines are suggested to reduce the risk of transmission o f H IV in sport: - In general the risk of HIV transmission as a result of sports participation is very low - The risk is higher in contact sports where there is a risk of transmission through contamination of open lesions, wounds or mucous membranes o f a noil-infected individual with infected blood or blood products - At present there is no risk o f transmission from saliva, sweat, tears, urine, respiratory droplets, hand-shakmg, swimming pool water, communal bath water, toilets, food or drinking water b. Specific guidelines for sportspeople: The following are specific guidelines for the individual sportsperson to reduce the risk o f H IV transmission during sports: - A sportsperson who engages in high risk behavior (Table 1) is advised to seek medical attention regarding pos- - S ^ r t ̂ s r a ^ w i l i i known H IV infection should seek medical and legal counselling before considering further participation in sport in order to assess risks to their own health as well as the theoretical risk of H IV trans­ mission to other sportspeople , . . . . , . - Sportspeople with known H IV infection should inform medical personnel of then condition if they sustain an open wound or skin lesions during sports participation so that these can be managed appropriately c. Specific guidelines for sports administrators: Sports administrators, including coaches and managers have special opportunities for meaningful education of sportspeople with respect to H IV disease. They should encourage sportspeople to seek medical counselling where appropriate. Finally, they also have an important role in ensuring that adequate medical care is available for th en sportspeople. d. Specific guidelines for medical personnel attending to sportspeople: Guidelines for medical personnel in preventing H IV disease in sportspeople are: - In general the guidelines for management o f HIV-positive patients that have been published in a policy state­ ment by the College of Medicine of South Africa can be applied by medical persomiel that attend to sports­ people with suspected H IV disease (Policy statement, 1991) . , , r ,, . , , - All open skin lesions sustained during sports participation shoidd be treated appropriately before allowing the sportsperson to return to the playing field - The following treatment of open skin lesions is recommended: immediate cleaning o f the wound with a suitable antiseptic such as hypochloride (bleach, Milton), 4/o gluteraldehyde (Cidex), organic iodines or 70% alcohol (ethyl alcohol, isopropyl alcohol) the open wound should be covered securely so that there is no risk o f exposure to blood or blood products prior to returning to the playing field - it is recommended that all first aiders and medical persomiel attending to sportspeople with open wound lesions wear protective gloves to decrease the risk o f H IV transmission to themselves and other sportspersons 18 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) The effects o f HIV infection on exercise performance The H IV epidemic will inevitably affect physically active people. This would include people that are phys­ ically active in sports (recreational or competitive) as well as manual laborers. Two o f the questions that will arise as a result o f H IV infection in physically active individuals are i) whether H IV disease affects the indi­ viduals ability to perform physical work and ii) whether regular physical work has a beneficial or perhaps a detrimental effect on the outcome o f the disease? These two questions have important implications for the sportsperson as well as advice regarding the occu­ pation o f an infected individual. There is very7 little information available in the m ed­ ical literature on the effect of IIIV infection on the abil­ ity to perform physical work. Indeed to date only a few studies have addressed this issue, hi one study exer­ cise performance was investigated in 32 patients with a clinical diagnosis o f A ID S (Johnson et al 1 9 8 9 ). Patients with documented AID S and complaining of dyspnea on exertion were enrolled in the study and their exercise performance was compared to a group of age, height and weight matched normals. H IV infected patients with evidence o f pulmonary infection, athero­ sclerotic heart disease, asthma, pre-existing pulmonary disease or other significant complicating medical disor­ ders were excluded from the study The exercise test to which patients and control sub­ jects were subjected consisted of an incremental exer­ cise test to exhaustion during which cardiorespiratory variables were measured. Arterial oxygen saturation was measured by finger oximetry. Spirometry was done before and immediately after the exercise test. The results of this study were that the patients with docu­ mented A ID S exercised to a significantly lower work­ load than controls, had a lower maximum oxygen uptake (VO2 max) than controls (not statistically signif­ icant), had similar maximal heart rates as controls, had a lower “ ventilatory anaerobic threshold” than controls, and did not have bronchospasm post-exercise. Nine subjects achieved an oxygen consumption (VO2) less than 81% o f the predicted whereas none o f the con­ trols exhibited this. The authors concluded that some AID S patients have impaired exercise performance and this was attributed to a central (cardiac) limitation. The possibility7 o f a direct effect of the H IV infection or its complications on muscle function was not considered. In another study exercise testing was included as part of a clinical trial evaluating the effectiveness of cor­ ticosteroids on Pneumocystis carinii pneumonia in AID S patients (Montaner et al 1990). In this study AID S patients with Pneumocystis pneumonia were ran­ domly allocated to either an experimental (receiving corticosteroids) or a control (receiving placebo) group and then monitored for 4 weeks. A maximal incremen­ tal exercise test was performed on days 0, 3, 7, 14 and 30. Effort tolerance was very poor in both groups on day 0. After treatment the exercise tolerance improved sev­ enfold in the treatment group whereas it remained the same in the control group. This positive effect was attributed to the prevention of early clinical deteriora­ tion by the administration of corticosteroids in the treatment group. It is obvious that this study was not primarily aimed at investigating effort tolerance in these patients. However, the results do indicate that Table 4: Summary of clinical trials: HTV infection and exercise PATIENTS EXERCISE PROGRAM M E CHARACTERISTICS OUTCOME (EXERCISE GROUP) REFERENCE FREQUENCY INTENSITY DURATION PERIOD TYPE H I V +ve (n=21) 2/week ? 1 hr 8 wks Various sports games - Reduced anxiety/ depression - CD4 count - CD4-Cd8 ratio Schlenzig et al, 1989 Asymptomatic H IV +ve (n=16) 3/week 70-80% o f H R max 4 5 min 10 wks - Cycle ergometer - Internal type training - Reduced anxiety/ depression - Non significant decline in NK - Trend for increase in CD4 count LaPerriere et al, 1991 H I V +ve (n=37) 3/week 60-80% 'of H R reserve (20 miris) 1 hr 12 wks - Cycle ergometer - Strength/ flexibility training - Improved muscle strength and endurance - No change in lymphocyte Rigsby et al,1992 SPORTS MEDICINE MARCH 1996 19 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) physical work is severely impaired in A ID S patients with associated pneumocystis infection and that this can be improved by appropriate therapy. The effects of regular exercise training on patients who were seropositive for the HIV but who were other­ wise asymptomatic, have also been documented. In one study 4 5 male volunteers who were allocated randomly' to an exercise and a counselling group (Rigsby et al, 1992). The groups were well matched according to m od­ ified Walter Reed criteria. The patients in the training group underwent exercise training consisting o f cycling, weight-training and flexibility exercises for 12 weeks. Exercise testing and immunological parameters were assessed before and after the training period. One of the significant findings o f the study was that the trained group showed evidence of adaptation to exer­ cise. This study therefore indicated that 12 weeks exer­ cise training in H IV seropositive patients can result in improved physical work capacity. In summary, patients with AID S appear to have impaired physical work capacity, the precise mecha­ nism of which is not clear. Asymptomatic patients with H IV disease appear to respond well to exercise training. The effects of regular physical activity on the out­ come o f HIV infection It is well recognized that an acute bout o f physical exer­ cise, as well as exercise training, has significant but variable effects on a number of immunological parame­ ters (Keast et al, 1988, McCarthy et al, 1988, Nehlsen- Cannarella et al, 1 991, Nieman et al 1 989, Nieman et al 1991, Oshida et al, 1988, Ricken et al, 1990). An acute bout of exercise will result in a leucocytosis, the magni­ tude o f which is related to the intensity o f exercise, the duration o f exercise and the state of exercise training o f the athlete (McCarthy et al, 1988). The nature o f the leucocytosis is variable and can either be a predominant neutrophilia or a predominant lymphocytosis. Furthermore, changes in lymphocyte subsets can also occur in response to an acute bout of exercise (Oshida et al, 1988). It has been documented that there is an increase in the absolute cell numbers o f all lymphocyte subsets, but that the increase is greater in B cells com­ pared to T cell subsets; thereby decreasing the T cell to B cell ratio (Keast et al, 1 988, McCarthy et al, 1988). It has also been demonstrated that a greater increase occurs in T 8 compared to T 4 cells during exercise; thereby decreasing the T 4 /T 8 ratio (McCarthy et al, 1988). hi addition, total l y m p h o c y t e proliferation to antigens and mitogens is typically reduced in response to exercise (Keast et al, 1988). The response of T lymphocytes to an acute bout of exercise has clear implications for individuals infected by the HIV. O f particular importance is the effect of exercise and exercise training on T cell counts and the C D 4 /C D 8 ratio. To date there are no published studies on the possible association between a programme of regular physical activity and the long term clinical out­ come of H IV infection. However, it has been suggested by long term AID S sufferers that regular exercise con­ tributed to their longevity (Solomon et al 1987). In recent years, several groups of investigators have been concerned with and have published data on the effects of exercise on the clinical course of H IV infected individuals. The results o f three well controlled ran­ domized clinical trials on the influence of regular exer­ cise training on immunological and psychological para­ meters in H IV positive patients are presented in Table 4. hi one of the earliest reports from the University of Miami, the beneficial effects o f regular exercise training on C D 4 cells o f HIV-infected individuals has been doc­ umented. hi tliis stud}', 10 weeks of exercise training at moderate intensity (< 80% o f maximal heart rate), for 4 5 minutes three times a week resulted in an increase in C D 4 cells (LaPerriere, 1 9 91). In another aspect o f the stud}', high risk individuals who were regular exer­ cisers, showed less anxiety and depression after receiv­ ing the news that they were H IV seropositive. Exercise appeared to provide a “buffer” to the psychological sequelae of a powerful acute stressor in these patients. The findings from the group at the University of Miami have the following possible practical applications: i) that exercise can play a beneficial role in the pre-HIV test counselling of potentially infected patients, and ii) that regular, moderate intensity exercise can play a role in the management of early, asymptomatic individuals with H IV infection (Calabrese et al 1993). Recently, specific recommendations on the role o f regular exer­ cise in the management o f patients with H IV disease have been made. These are summarized hi Table 5. Summary Regular participation in physical activity is advocated as an important preventative health measure. However, the global pandemic of H IV infection is likely to influ­ ence physically active individuals. The association between H IV infection and physical activity therefore requires attention. In this review the risk of H IV trans­ mission during sport and physical activity, the effects of Table 5: Recommendations for exercise in patients with HIV infection a. General Before initiating any type o f exercise-training, all IilV- infected individuals regardless of age or stage of disease should: - have a complete physical examination - discuss exercise plans with a physician or exercise specialist - comply with ACSM testing and prescription guidelines.' b. Healthy asymptomatic HIV seropositive - Unrestricted exercise activity - Continue competition - Avoid overtraining c. AIDS-related complex - Continue exercise training on symptom listed basis - Avoid strenuous exercise - Reduce or curtail exercise during acute illness. d. Diagnosed AIDS - Remain physically active - Continue exercise training on symptom limited basis - Avoid strenuous exercise - Reduce or curtail exercise during acute illness 20 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) H I V in fe ctio n on e x e r c is e p e rfo rm a n ce , and th e e ffe c ts o f regu lar p h y sica l activity on th e o u tco m e o f H IV in fection w as d is cu s s e d . REFERENCES: Alcena V: Boxing and the transmission o f IIIV New York Slate J Med 1988; July: 392. American A cadem y o f Pediatrics: Human Immunodeficiency virus I Acquired immunodeficiency syndrome (A ID S) virusJ in the athletic setting. Pediatrics 1991; 8 8 (3 )- 640-641. Astrand PO: Why exercise? Med Sci Sports Exerc 1992; 24- 640-641. Australian Sports Medicine Federation: Infectious disease policy. Sports Medicine News (Suppl to Sport Health) 1992; 1 0 (1 ): 8-9. Brown JR, Phillips RY, Brown CL, et al: HIV/AIDS poli­ cies and sports; the National Football League. Med Sci Sports Exerc 1994; 2 6 (4 ) : 403-407. Calabrese L, LaPerriere A : Human immunodeficiency virus infection, exercise and athletics. Sports Med 1993a; 1 5 (1 ): 6- 13. Calabrese L: H IV infection, exercise and athletics. Invited paper at the 40th Annual meeting o f the American College o f Sports Medicine, June 2-5, 1993. Friediand GH, Klein RS: Transmission o f the human immunodeficiency virus. New Engl J Med 1987; 317: 1125- 1135. Goldsmith MF: When sports and IIIV share the bill, smart money goes on common sense - medical news and perspectives. JAMA 1992; 277: 10-13. Human Sciences Research Council on sports participation in South Africa 1982 Ijsselmuiden CB, Steinberg MH, Padayachee GN et al: A ID S and South Africa - towards a comprehensive strategy. Part 1. The workl-wicle experience. SAMJ 1988a, 73: 455-460. Johnson ,IE, Anders GT, Blanton HM et al: Exercise dys­ function in patients seropositive for the human immunodeficien­ cy virus. American Review o f Respiratory Disease 1990; 141: 618-622. Keast, D, Cameron K, Morton A R : Exercise and the immune response. Sports Med 1988; 5: 248-267. LaPerriere A , Fletcher MA, Klimcis N, et al: Aerobic exer- cise training in an AIDS risk group. Int J Sports Med 1991; 12: S53-S57. LaPerriere A , O ’Hearn P, Ironson G, et al: Exercise and immune function in healthy H IV antibody negative and positive gay males. Proc Ninth Ann Scientific Sessions o f Soc Behavioral Med, Boston, March 27-30, pp 28, 1988. Lifson A R : D o alternate modes for transmission o f human immunodeficiency virus exist? A review. JAM A 1988; 259 (9 ) ■ 1353-1356. Loveday C: IIIV disease in sport. Medicine, Sport and The Law Chapter 5 pp 81-86. 1989. McCarthy DA, Dale MM: The leucocytosis o f exercise. A review and model. Sports Med 1988; 6: 333-363. MMWR: Pneumocystis pneumonia - Los Angeles MMWR 1981a; 30: 250-252. MMWR: Kaposi s sarcoma and pneumocystis pneumonia among homosexual men - New York City and California MMWR 1981b; 30: 505-308. MontanerJSG, Lawson LM, Levitt N el al: Corticosteroids pre­ vent early deterioration in patients with moderately severe pneit- mocystis carinii pneumonia and the acquired immunodeficiency syndrome (AID S). Annals o f Internal Medicine 1990; 113-14-20 Moodie JW: Serology o f AIDS. S/1 J o f Continuing Medical Education 1988b; 6: 58-67. Moodie JW: The AIDS epidemic. .S/1 J o f Continuing Medical Education 1988a; 6: 37-46. Nehlsen-Cannaretla SL, Nieman DC, Balk-Lamberton AJ, et al: The effects of moderate exercise training on immune response. Med Sci Sports Exerc 1991; 2 3 ( 1 ) : 64-70. Nieman DC, Berk LS, Simpson-Westerherg M, et al: Effects o f long-endurance running on immune system parameters and lym­ phocyte function in experienced marathoners. Int J Sports Med 1989; 1 0 (5 ) : 317-323. Nieman DC, Nehlsen-Cannarella SL, Donohue KM, et al: The effects of acute moderate exercise on leukocyte and lymphocyte subpopulations. Med Sci Sports Exerc 1991; 2 3 ( 5 ) : 578-585. Oshida Y, Yamanouchi K, Hayamizu S, el al: Effect o f acute physical exercise on lymphocyte subpopulations in trained and untrained subjects. Int J Sports Med 1988; 9 ( 2 ( : 137-140. Policy Statement from the College o f Medicine o f South Africa. Management o f HIV-positive patients. SAMJ 1991; 79- 688-690. Position Statement: World Health Organization (W H O ), World Federation of Sports Medicine (FIM S): Consensus state­ ment on A ID S and sports. Br J Sports Med 1989; 23 ( 2 ) : 132. Ras GJ, Simpson IW, Anderson R, et al: Acquired immun­ odeficiency syndrome: A. report o f two South African cases. SAMJ 1983; 64: 140-142. Ricken KII, Rieder T, Ilauck G, et al: Changes in lymphocyte subpopulations after prolonged exercise. Int J Sports Med 1990' 1 1 (2 ): 132-135. Schall R : On the maximum size of the A ID S epidemic among the heterosexual black population in South Africa. SAMJ 1990- 78: 507-510. Schoub BD, Smith .1 A. Johnson S, et al: Considerations on the further expansion o f the AIDS epidemic in South Africa: 1990. SAMJ 1990; 77: 613-618. Sher R: A ID S - Clinical diagnosis and treatment. .S71 J ofCME 1988; 6: 31-36. Sheridan JW: Blood-borne infections in sport. Sports Medicine News (Supplement to Sports Health) 1992; 1 0 (1 ): 2-7. Solomon GF, Tomoshok LA: A pscychoneuroimmunologic perspective on AIDS research: questions, preliminary findings and suggestions. J Appl Soc Psychology 1987; 17: 286-308. Torre D, Sampietro C, Ferraro G et al: Transmission ofH IV - 1 infection via sports injury. Lancet 1990; 335: 1105. Ziegler JB, Cooper DA, Johnson RO, et al: Post natal trans­ mission o f AIDS - Associated retrovirus from mother to infant. Lancet 1985; i; 896-898. [f] SPORTS MEDICINE MARCH 1996 21 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) READERSHIP SURVEY If yo u wish to continue receivin g this jou rn al, free of ch a rg e , p le a s e fill in the form b elow and return it to: Glenbarr Publishers cc Private Bag X I 4 Parklands 2121 Name:............................................................................................................................... Address:........................................................................................................................... Code:.............. SPECIALITY 22 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Vitamin C as effective as combinations of anti-oxidant nutrients in reducing symptoms of upper respiratory tract infection in ultramarathon runners. Peters, EM* M.Sc.(Med) Goetzsche, JM* B. PhysJJd Joseph, LE* M.Ed. Noakes, TD**(M BBCh, MD, FACSM) Abstract The effect o f anti-oxidant supplementation on the inci­ dence of symptoms of upper-respiratory-tract infection (URTI) was determined during the fortnight following the 1 9 9 3 Com rades Marathon (90k m ). Runners (n =178) and sedentary matched controls (n=162) were randomly divided into groups receiving 500m g Vit C (C; n=86), 500m g Vit C and 4 0 0 1U Vit E (CE; n =90) or 300IU Vit E, 300m g Vit C and 18m g Beta Carotene (CEB; n=73) or placebo (P; n =93) daily for 21 days prior to participation in the ultramarathon. Total pre-race dietary vitamin and mineral intakes and post-race self- reported URTI symptoms were recorded in all subjects (n=340). The incidence o f the URTI symptoms in P run­ ners (40.4% ) was significantly higher (p<0.05) than that in C (15,9% ) and CEB (20,0% ) runners, and also greater than that in matched, non-running controls receiving placebo (24,4% ). The group o f runners reporting the lowest incidence of URTI symptoms during the post­ race period, had the lowest mean age and the highest (i) total mean daily Vit C intake (1 0 0 4 mg); (ii) pre-race training status and (iii) percentage of black runners. This study suggests that Vitamin C alone is as effec­ tive as combinations o f Beta Carotene, Vitamin E and Vitamin C in reducing the incidence of post-race URTI symptoms and that age, training status and genetic make-up also may influence the susceptibility to the development of URTI symptoms in ultramarathon runners. Key Words: Anti-oxidant Vitamins, Upper Respiratory Tract Infections, Ultramarathon Runners. * Division of Physical Education, University of the Witwatersrand, Johannesburg, South Africa. * * MRC Bioenergetics of Exercise Research Unit in the Sport Science Institute of South Africa, Medical School, University of Cape Town, South Africa. Correspondence: Edith Peters Division of Physical Education, University o f the Witwatersrand, Johannesburs, 2001, South Africa. Tel: (011) 7 1 6 -5 7 1 8 Introduction Two separate epidemiological surveys performed on ultradistance runners1 ~ have reported an increased inci­ dence of symptoms of upper respirator}' tract (URTI) following participation in ultrainarathon events. A sub­ sequent study5 found that daily administration of 600m g Vitamin C for three weeks prior to the 90km Comrades Marathon, resulted in a significantly lower (p<0.05) incidence of symptoms o f infection in runners during the fortnight after the race, compared to runners ingesting placebo. This was attributed to the anti-oxi­ dant properties of Vitamin C, which suggests that ath­ letes participating in prolonged exercise have an increased daily Vitamin C requirement. ' . Evidence from more recent studies45 is that the anti­ oxidant nutrients may be more effective when used in combination. The aim of this study was therefore to compare the efficacy o f supplementation with combina­ tions of Vitamin E, Vitamin C and Beta Carotene and Vitamin C alone in reducing the incidence o f post race URTI in ultra marathon runners. Method The protocol was approved by the Committee for Research on Human Subjects o f the University o f the Witwatersrand. Two hundred and twenty entrants for the 1993 Comrades Marathon volunteered to partici­ pate in the study. Each runner was matched (n=220) with a control of similar age who resided with the run­ ner, but did not participate in running regularly. A dou­ ble-blind, placebo-controlled study design was used in which the runners, in addition to their matched, non- running controls, were randomly divided into four groups. Each group received either anti-oxidant supple­ ments or placebos for three weeks prior to the race. The pre-race training status, state of health and dietary vit­ amin and mineral intake o f athletes and their age- matched controls was recorded by means of a question­ naire which each runner and control subject completed prior to the race. Demographic data including running distance per week, average running speed, number of weeks spent training and the number o f other ultrama­ rathons in which the athlete had recently participated were also recorded, h i addition, the pre-race incidence of self-reported symptoms o f URTI was documented. Runners with a history7- of sinusitis, hay-fever or both were excluded. Each runner and matched control (n=55) was required to take three tablets o f similar appearance daily. These contained either 500m g Vit C (C), 500m g Vit C & 400IU Vit E (CE), 300m g Vit C & 300IU Vit E, 18 mg Beta SPORTS MEDICINE MARCH 1996 23 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Carotene (CEB) or lactose as placebo (P). The total daily vitamin A, C and E intakes including that derived from any additional vitamin and mineral used by the athlete of all subjects was determined by using the Dietary Manager computer programme (Program Management, Randburg, South Africa). For the purpose o f this study, the total vitamin A, C & E intake of each subject was thus calculated from the sum of the (i) daily dietary intake, (ii) additional supple­ ments used and (iii) the anti-oxidant supplements given to the subjects. Two weeks after the race all runners and controls who had originally volunteered to participate in the study were telephonically interviewed and questioned regarding: (i) whether the prescription of supplements had been adhered to or not; (ii) the race distance cov­ ered and the time taken by each athlete to complete this distance; (iii) the incidence and duration of symp­ toms of URTI. The number and duration o f self-report­ ed symptoms including sneezing, running nose, sore- throat, cough and fever were documented. All reports of trivial symptoms were excluded by including in the final analysis only reports of single URTI symptoms which lasted >1 (lay or a combination o f at least 2 URTI symp­ toms each o f which lasted < I day. The training status ratio of each runner was calculat­ ed from the following formula: Weekly training distance (km) • no o) weeks spent in training average speed at which those kilometres were covered As in our previous study®, runners who reported a ratio of > 4 5 0 fell into the high-training status category, whereas those with a ratio < 3 0 0 were classified in the low training status category. Statistics A chi-square statistic was used to establish whether the incidence o f symptoms o f URTI was significantly differ­ ent between the four groups o f runners and controls. Multivariate analysis of variance and several one-way analyses of variance were used to analyze the signifi­ cance o f the difference between the four groups in terms of age, Vitamin C, E and Beta Carotene intake and training status ratio. For all statistical analyses the Statgraphics and Excel computer software programs were used and the level of significance were set at 0.0 5 . Results O f the initial 22 0 runners and matched controls, 178 runners (23 female; 155 male) and 162 (116 female ; 4 6 male) controls compiled fully with the requirements of the study. Reasons for exclusion from the study includ­ ed a prev ious history o f allergic rhinitis, failure to take the prescribed medications, failure to complete at least 6 0 km of the race and inability to establish contact with the subjects after the race. The size, gender distribution and mean age o f the 4 groups o f runners and their matched controls is given in Table 1. Among the runners who ranged in age from 19 to 6 5 years, 4 6 were < 30 y old, 119 were aged between 31 and 50 y and 13 were > 5 0 y in age. Although the two groups with the highest incidence o f reports o f URTI possessed the highest mean age, this was not signifi­ cantly different from the mean age o f the groups with lower incidence of infection (p>0.05). Table 1: The size, gender distribution and age (+ /- SD) o f the 4 study groups (n=340) mean EXPERIMENTAL RUNNERS CONTROLS GROUP (n 178) (n = 162) N Age N Age M F (Years) M F (Years) Group C 44 34,3 41 33,1 36 8 (5,2) 11 30 (9,5) Group CE 47 37,6 43 33,7 41 6 (8,4) 11 32 (9,2) Group CEB 40 35,1 33 29,7 36 4 • (10,0) 8 25 (11,9) Group P 47 39,2 45 32,8 42 5 (9,5) 16 29 (11,8) The total mean Vitamin A, E and C intakes of the run­ ners in each o f the four groups is shown in Table 2. The highest total mean intake of Vitamin C was reported in group C, whereas the P group reported a mean intake of 585m g o f Vitamin C. Groups CE & CEB also reported high mean intakes o f this Vitamin. Group CEB was the only group with a Vitamin A intake which exceeded the RD A for sedentary individuals'', whereas group CEB was the only group which exceeded the RDA0 of Vitamin E for sedentary7 individuals. The group with the lowest incidence of infection (C) reported a total mean Vitamin C intake of 1004m g. T a b le 2: The mean Vitamin A , C and E intakes o f the runners ( n=l 78) in the 4 groups. GROUP C GROUP CE GROUP CEB GROUP P Food Vit A (IU) 3170 4405 3915 3110 Sources Vit C (mg) 72 93 95 80 Vit E (IU) 25 22 26 18 Additional Vit A (IU) 1446 1737 2348 2992 Supplements Vit C (mg) 432 305 271 505 Vit E (IU) 12 22 8 43 Anti-oxidant Vit A (IU) - . 30 000 - Supplements Vit C (mg) 500 500 300 - provided Vit E (IU) - 400 300 - Total Vit A (IU) 4616 6142 36 263 6102 Vit C (mg) 1004 893 665 585 Vit E (IU) 37 444 334 61 24 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) The incidence of symptoms o f URTI in the runners and controls are given in Figure 1. The difference between the incidence of symptoms o f infection in die runners ingesting placebo (40.4% ) and their sedentary, matched controls (2 4 .4 % ) was not significantly different (X 2= 1 .9 9 ; p = 0.16). The lowest incidence of infection amongst the runners (15.9% ) was reported in group C. This was significantly different (X 2= 5 .5 4 ; p < 0 .0 5 ) from the incidence o f URTI symptoms in group P A 20% inci­ dence o f infection was reported hi group CEB. The inci­ dence o f symptoms of URTI in group CE was also sig­ nificantly lower than in group P (X 2 = 6 .2 4 ; p > 0.05). The incidence o f symptoms o f infection in group CE (25.6%>) was not significantly different (p > 0 .0 5 ) than the incidence in group P (40.4% ). The incidence, nature and mean duration o f the symptoms o f URTI among nmners and control subjects is presented in Table 3. The m ost common URTI symp­ toms reported by runners in the 4 groups were nasal (n = 35). Included in this category were reports of running noses and sneezing. Symptoms lasting more than 7 days occurred in 20 cases (nasal), 13 cases (sore throat) and 12 cases (coughing). Twelve o f the runners reported fever in conjunction with their URTI symptoms. Only 24,2% o f the reported runners symptoms lasting 1-3 days. The mean duration o f symptoms in die runners was not significantly different from the mean duration o f symptoms in the control subjects (p > 0.0 5 ). Although the mean duration of symptoms was higher in runners on placebo than in runners who received the different combinations o f anti-oxidants, this difference was not statistically significant (p > 0.05). Table 3: Incidence, nature and duration o f post­ race symptoms of URTI among runners and control subjects. EXPERIMENTAL GROUP 0/o MEAN (± SD) N SYMPTOMATIC TRArNING STATUS RATIO Group C Group CE Group CEB Group P 42 20,2* 311 (±150)** 47 25.8 274 (±127) 40 16,7* 328 (±166)** 47 40,4 236 (±111) * P < 0 .0 5 vs Group P ** P <0.01 vs Group P The incidence o f infection in the low, medium and high training status groups is shown in Figure 2. Those n m ­ ners who reported a low pre-race training status (<250) group reported the highest incidence o f infection symp­ toms. This finding was confirmed when the incidence o f post-race URTI symptoms was related to the mean training status o f die 4 groups o f nmners (Table 4). The two groups with an incidence o f URTI symptoms of more than 25%, reported the lowest mean training sta­ tus. The difference between the training status of groups C and CEB (possessing the lowest incidence of infection) and groups CE and P (possessing the highest Figure 1: Incidence o f Symptoms o f URTI in runners (n = 178) and controls (n post race period. 162) during the 14 day RUNNERS (n = 178) (x* = 8,20; p < 0,05) 60 50 (0 o ■ 0,05) 12.2% I 23.3% I 15.1% 24.4% Group C Group CE Group CEB Group P Group C Group CE Group CEB Group P Symptomatic Asymptomatic * Significantly different from Group P (p<0,05) SPORTS MEDICINE MARCH 1996 25 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Figure 2: The incidence o f post-race URTI symptoms in low, medium and high training status groups (n=176) N u m b er 50 — o f S u b je c ts 25 — 31,1% \ \ \ \ v 24,6% \ \ \ | \ \ ] Sym ptom atic □ N on-sym ptom atlc X2 = 2,21 p > 0,05 17,2%. <300 300-450 >450 LOW MED HIGH TRAINING STATUS RATIO incidence of infection) was highly significant (p > 0.01). When the incidence o f URTI symptoms were related to weekly training distance completed in preparation for the race, this trend was confirmed. Once again, the run­ ners who had done the least pre-race training, reported the highest incidence of URTI symptoms. A total o f 16 black runners participated in the study. None of these athletes reported symptoms of URTI. When excluding the black runners from their respective groups, the percentage incidence o f infection symptoms in the respective groups was 2 5 ,7(C); 4 1 ,3(F); 26,7(C E) and 2 3 (CEB). The difference between the three groups receiving additional anti-oxidant supplementation was not significant (p > 0.0 5 ). Despite a substantial differ­ ence in percentage incidence in the placebo group and the groups receiving anti-oxidant supplementation, this difference was no longer significant ( p > 0.05). No relationship between running time and incidence o f URTI symptoms in the four groups was found in this study. Although the incidence was highest (35,5%) in those runners who took >10hrs to complete the race, this incidence was not significantly greater than the incidence in groups taking 7 -8 hrs (23.5% ) and 8 -9 hrs (27,8% ) to finish the race. Discussion The data obtained in this study confirms our previous findings12 8,7 o f a greater incidence o f post-race symp­ tom s of infection in ultramarathon runners compared to sedentary controls (Figure 2). The comparatively lower general incidence of symptoms in this study than in our previous study1 must be seen in the light of the fact that (i) in this study, reports o f symptoms lasting one day or only part thereof were not included in the final calcula­ tion and (ii) prevailing virological or bacteriological counts may have varied greatly at the time that these two separate studies were undertaken. This study confirms previous findings3 that daily intake o f an excess of l g of Vit C is effective in lowering the incidence of symptoms of URTI during the post­ race period. Although the incidence o f symptoms of URTI was substantially lower in all three groups o f run­ ners receiving anti-oxidant supplementation than in the group o f runners receiving placebos, no correlation was obtained between the total amount of anti-oxidant nutrients ingested and the incidence o f symptoms of URTI. Rather, it was the group with the highest total daily intake of Vit C which had the lowest incidence o f URTI symptoms. Several factors could account for this. Table 4: The mean training status ratio and incidence o f post race URTI symptoms in the 4 groups of runners (n=176) __________ _______ ____________ EXPERIMENTAL GROUP P ost Race Symptoms Nasal Symptoms Sore Throat Cough Fever and URT Symptoms Total Symptomatic * * Mean Duration o f Symptoms A : RUNNERS Group C Group CE Group CEB Group P (n=44) (n=47) (n=40) (n=47) 11 duration n duration n duration n duration 5,3 10 5,8 5,8 9,0 9 4,7 2 3,0 2 . 12 7,0 1,8 7 5 4 4 8 7,6 14 5,8 12 4,5 4,: 4,3 8 5 19 6 I 7,8 6,4 5,8 5,6 B : CONTROLS Group C Group CE Group CEB Group P (n=41) (n=43) (n=33) (n=45) n duration 11 duration 11 duration n duration 7,0 7,8 9.6 14.6 8 22,8 8 9,3 8 11,1 2 11 9,4 17,5 15,2 0 3 1 6 5 3.2 11 7,8 1.3 8 8,1 77,0 0,0 4 11 2,3 10,3 2,0 6,9 Nasal symptoms include runny nose and sneezing. ** No. of persons in the group who presented with 1 or more symptoms lastmg_ 1 day or 2 more symptoms lasting < 1 day Duration = mean no. of days 26 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) Vitamin C is regarded as a first line anti-oxidant in the defence against phagocyte- derived reactive oxi­ dants8010. These immunosuppressive free radicals are known to be autotoxic, causing inhibition o f chemo- taxis, phagocytosis, the proliferation o f T-lymphocytes and B -lymphocytes as well as the cytotoxic activity o f natural killer cells 111213. Evidence is mounting in favour o f Vitamin C- mediated neutralization o f these reactive oxidants8910. The relatively smaller protective effect of vitamin E and Beta Carotene supplementation may, be partially attributable to the slow elevation in plasma Vitamin E and Beta Carotene levels15 and the fact that a 21 day supplementation period is too short to elevate plasma levels to reach protective levels. Secondly, variance in age14, training status15, environmental training condi­ tions'", and genetic make-up between the groups stud­ ied, may have obscured the effect of the other anti-oxi­ dant nutrients. A s in our previous study3, age does not appear to have played a significant role in the risk o f infection. Training status, however, appeared to be an important factor. The highest incidence of symptoms o f URTI was found in those runners who fell into the low training status category (Figure 2). Further confirmation o f a possible beneficial effect o f training is found when examining the mean training status o f the four groups. It was found that the two groups possessing the high­ est training status had the lowest incidences o f infec­ tion symptoms (Table 4). These findings were further supported when the incidence o f URTI symptoms was analysed as a function o f weekly training distance. Two factors m ight support, this finding. First, endurance training results in a lower catecholamine levels at a given exercise workload. This is potentially important as catecholamines affect free radical produc­ tion16. Second, endurance training increases concentra­ tions o f endogenous antioxidant enzymes in skeletal muscle15. That endurance training exerts a protective effect on oxidative stress thus warrants further investi­ gation in humans. The finding that Black runners who participated in this study did not develop infection symptoms, also requires further investigation. This difference might be explained by chance; socio-economic or hereditary fac­ tors may also have played a role. To conclude, the findings o f this study appear to indicate that large intakes o f Vitamin C alone OlOOOmg) are more effective than combinations of Vitamin E, Vitamin C and Beta Carotene in lowering the incidence of URTI in ultradistance runners. This study, however, also indicates that besides Vitamin C inges­ tion, training load and ethnic background, are impor­ tant variables which may influence the susceptibility to infection in ultramarathon runners. REFERENCES 1. Peters EM. Ultramarathon running fails to increase sus­ ceptibility o f ultramarathon runners to infections. S. Afr. J. Sports. Med. 1990;5:4-8. 2. Peters EM, Bateman ED. Ultramarathon running and upper respiratory tract infections. S. Afr. Med. J. 1983;64:582- 584, 3. Peters EM, Goetzske JM, Grobbelaar B, Noakes TD : Vitamin C supplementation reduces the incidence o f post-race symptoms o f upper respiratory tract infections in ultradistance runners. A m J clin Nutr, 1993:57:170-174. 4. Packer JE, Slater TF, Wilson RI.. Direct observation o f a free radical interaction between vitamin E. and vitamin C Nature. 1979;278:737-738. 5. Sharma MK, Buettner GR. Interaction o f Vitamin C and Vitamin E During Free Radical Stress in Plasm a: An ESR Study. Free Rad Biol & Med 1993;14:649-653. 6. Committee on Dietary Allowances, Food and Nutrition Board, National Research Council. Recommended Dietary Allowances. 10th Edition, Washington DC : National Academic Press, 1989. 7. Peters EM. Cambell A , Pawley L. Vitamin A fails to increase resistance to upper respiratory infection in distance runners. S. Afr. J. Sports Med. 1992;7:3-7. 8. Bendich A , Machlin LJ. Burton GW, Wayner DDM. The anti-oxidant role o f Vitamin C. Adv Free Radical Biol Med. 1986;2:419-444. Irt'i B, England L, Am es BN. A scorbate is an outstanding anti-oxidant in human blood plasma. Proc Nat Acad Sci- 1989;86:6377-6381. 10. Anderson R, Smit MJ, Joone GK, Van Staden AM. Vitamin C and cellular Immune Functions: Protection against hypochlorus dehydrogenase and ATP generation in human leukocytes as a possible mechanism o f ascorbate immunostimu- lation. A nn N.Y. Acad. Sci. 1982;587:34-48. 11. Anderson R. Phagocyte-derived reactive oxidants as medi­ ators o f inflammation-related tissue damaqe. S. Afr J Sri 1991;87:594-596. 12. Babior BM. Oxidants from Phagocytes: agents o f defence and destruction. Blood 1984;64:959-964. 13. Herbaczynska-Cedro K, Wartanowicz M, Panceczenko- K resowska B, Cedro K, Klosiewicz-Wasek B, Wasek W: Inhibitory effect of vitamins C and E on the free radical produc­ tion in human polymorphonuclear leukocytes. Europ J Clin Invest. 1994;24:316-319. 14. Ji II/, Mitchell EW, Thomas DP. The Effect o f exercise train­ ing on anti-oxidant and metabolic function in senescent rat skeletal muscle. Gerontology. 1991;37:317-325. 15. Machlin U , Bendich A : Free radical tissue damage: pro- tective r°t(‘ ° f anti-oxidant nutrients FASEBJ. 1981;51:441- 16. Fridowich I, Freeman B. Anti-oxidant defence in the lunq Ann Rev Physiol 1986;48:693-792. 17. Weiss SJ. Tissue destruction by neutrophils. New Enal J med 1989;320:365-376. 18. Viru A . Hormones in Muscular Activity. Boca Raton FI : CRC Press, 1985. ' r~i SPORTS MEDICINE MARCH 1996 27 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) South African Journal o f Sports Medicine Instructions for authors Material submitted for publication in the SAJSM is accepted on condition that it has not been published elsewhere. The management reserves the copyright of the material pub­ lished. 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All manuscripts and correspondence should be addressed to: The Editor, South African Journal of Sports Medicine, PO Box 115, Newlands,7725. 28 SPORTS MEDICINE MARCH 1996 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) A social cognitive perspective on promotive and preventive health behaviour in post-apartheid South Africa I Miller Abstract Non-communicable diseases or chronic diseases of lifestyle are on the increase amongst all South African population groups. There are, however, disparities in the health profile of black and white communities which can be attributed to the discriminatory health care services of the apartheid era. Sport and Exercise Scientists who strive to enhance health and prevent disease and injury by facilitating participation in physi­ cal activity and sport, should therefore endeavour to address these imbalances. However, their efforts to promote health and fitness amongst all communities should be guided by an understanding of the social, psychological, political and cultural factors which could foster hypokinetic lifestyles or deter participation in health-related physical activity. Albert Bandura’s social-cognitive theory is therefore used to explain and predict health behaviour in the South African context. It is further advocated that research in the sport and exercise domain shoidd be re-orientated to develop a knowledge base which could guide the design and implementation of effective community-based, health- related physical activity programmes in post-apartheid Sou til Africa. Introduction Professionals and academics concerned with the pro­ motion of health and fitness through sport, physical exercise and recreation, could be regarded as promo­ tive and preventive health care workers. As such, they should be concerned about indications that non-com­ municable diseases or chronic diseases of lifestyle are on the increase amongst all population groups in South Africa. As far back as 1988, life-style related diseases already accounted for 24,5% of all deaths reported in South Africa. Research conducted in 19 9 2 revealed that 55% o f the population within the 1 5 -6 4 age group were in need of life-style modification and that 16,5% received medical treatment for preventable hyperlipi- daemia and hypertension (in that particular year),1 In addition to the physical diseases referred to above, it can also be expected that the mental health of South African citizens has been affected by the political turmoil which has prevailed in South Africa over the past few decades. (Van Rensburg and Benatar 1 9 9 3 )' Correspondence: I. Miller Department of Human Movement Studies, University of the Western Cape, E Bag X 17 Belville 7535 Tel: (021) 959-2350 ascertained that high profiles of stress, trauma, power­ lessness and instability exist in non-white communities. They further cautioned that South Africans have inter­ nalised apartheid to the extent that it influences their “psychic make-up and self-image,... minds and emo­ tions,... attitudes and behaviour patterns” .' It can therefore be presumed that South Africans’ perceptions of themselves, as well as their views of themselves in relation to society, have been influenced in a positive or negative manner by their socio-political experiences, and that this has ultimately impacted on the psycho­ logical (and general) health and social well-being o f our nation. The health problems cited above can certainly be addressed by Human Movement Specialists (sport and exercise scientists, biokineticians, physical educators, recreation officers) by means of health-related physical activity programmes or rehabilitative movement thera­ py. Sufficient evidence exists to verify' that regular phys­ ical activity can bring about: * modifications in blood fat profiles and associated reductions in obesity: * reductions in blood pressure for moderately hyper­ tensive individuals; * reductions in coronary heart disease (CHD); * organic changes in the lungs and resultant increases in respiratory efficiency; * reductions in low back pain and postural defects; * preservation of joint and muscle function; * reductions in constipation through improved effi­ ciency o f the digestive system; * promotion of bone health and consequent reductions in fractures and osteoporosis in later life; * reductions in anxiety and depression; * reductions of the adaptations to psychological stress; * improvement of sleeping habits; * and enhancement of self-im age and self- confidence.3 8 Admittedly, improvement of health cannot be attrib­ uted to regular exercise alone and the positive impact of exercise alluded to above may be limited to specific populations under specific conditions. However, while the rehabilitative and curative value of exercise is acknowledged and advocated, it is regrettable that the preventive potential of regular physical activity is not promoted amongst all sectors of the South African com­ munity. X 9 observed that good health has been deemed more important for whites than for blacks and that a lack of interest in the health status of black patients has been deem ed more important for whites than for blacks and that a lack of interest in the health status of black patients has been discernible to date. Although this observation refers to the discriminatory7 provision of curative health care, the lack of sport, gymnasium and recreation facilities in black communities suggests that similar inconsistencies exist with regard to health SPORTS MBDICINE MARCH 1996 29 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) T h e h ealth plan p ro p o s e d by the A lriean National C on g ress a d v oca tes a “ re d ress of the negative e ffe c ts ol a p a rth eid h ealth ca re s e r v ic e s ’ . H ow ever, the top ics lu n lcr d iscu ssio n at the 1994 c o n g re ss o l th e S outh A frican F ederation for M ovem ent and L cis iu e S cie n ce s in d ica tes that th is d is cip lin e has not re-orientated it s e lf to the n e e d s o f the “ n ew ” South A frica. Instead, it a ffirm s the e m p h a s is w h ich H um an M ov em en t S cien tists place on u n d ersta n d in g the ca p a city and p e r ­ form an ce ol a relatively sm all percen ta g e ol the c o m - uuuiitv w h o m aintain active lifestyles anti w h o p a rtici­ pate in e lite , c o m p e titiv e s p o il. T h e valuable co n tr ib u ­ tion o f Sport S cie n ce , E xercise S cien ce and B io k in e tics in th is regard, e sp e cia lly In view o f S ou th A frica ’s re- entry into the international sport arena, is not c o n te s t­ ed. H ow ever, it can b e q u e stio n e d w h e th e r the d e b il i­ tating socia l, p olitica l, e c o n o m ic and nutritional va ri­ a b les w h ich im pact 011 th e m otor d ev elop m en t and ph ysical p erform a n ce ol the m ajority ol S ou th A fricans, d o c s not warrant m ore attention. M oreover, th is d is c i­ pline sh o u ld be c o n ce rn e d w ith the factors w h ich lo stcr h yp ok in etic lifesty les and d e te r h e a lth -se e k in g b e h a v ­ iour. A Social-Cognitive analysis ot Health Behaviour T h e W orld H ealth O rganization (W H O ) d e fin e d health a s an in teg ra ted , m u ltifa ce te d p h e n o m e n o n w h ich e n c o m p a s s e s p h y sica l, p sy ch o lo g ica l ;uid socia l well- bein g. S c h lc b u s c h 11 co n cu rre d that age, gen d er, p s y c h o ­ logical status, socio-cu ltu ra l and p olitica l e x p e rie n ce s, ed u ca tio n , religion , the m ed ia , netw ork s w h ich exist in society, a s well as p erson al b e lie fs , valu es and attitu d es c o u ld in flu en ce h e a lth beh avioiu '. H ea lth w o rk e rs sh o u ld th erefore a ck n ow led g e that in d iv id u a ls ’ p e r c e p ­ tions o f h ea lth and h ealth care w ill be in llu cn ccd by the recip roca l in teraction b e tw e e n th eir behavioiu-, internal m ak e-u p and the external environm ent w ith in w h ich they fu n ction .'' T h e socia l-cog n itiv e th eory p ro p o s e d by B andura c o u ld be used to account for the variability and c o n s is ­ tency w h ich exist w ith regard to p rom otiv e health b e h a v io u r in g en era l, and particip a tion in regular p h y s­ ical activity in particular. T he th eory p ostu la te s that ... b eh a v iou r is in flu en ced by th ree self-re g u la to r}’ m e c h a ­ n ism s op era tin g in c o n c e it: p erce iv e d se lf-clfie a cy for o u tco m e attainm ent, o u tcom e e x p ecta tion s, and p e r s o n ­ al g o a l-se ttin g ” . 1:1 It is su g g ested that p e r c e p tio n s about the o u tco m e o f the beh a v iou r (eg. m on etary rew ard, socia l approval, se lf-sa tisfa ction or h ealth b e n e fits ) will in flu ence d e c is io n s abou t p a rticip a tion in p h ysica l activity. Sim ilarly, in d iv id u a ls’ b e lie fs of se lf-cffica cy (sk ills, in form ation and a bility) serve as an internal or personal form o f behavioiu- con trol w h ich d e term in e involvem ent w ith p h ysical activity.1'* T h e notion that h ea lth behavioiu- is in flu en ced by person al p e r c e p tio n s and b e lie fs, is fu rth er d e m o n ­ strated by th e “ lo c u s -o f-c o n lr o l” th eory d e lin e a te d by Lau . ‘4 H e co n te n d e d that in d iv id u a ls w h o b eliev e that they have 110 o r little con trol o v er th e negative situation in w h ich th ey find th e m s e lv e s , m ay d e m o n s tr a te “ le a rn e d h e lp le s s n e s s ” . Sim ilarly, som e in d ivid uals, the so -ca lle d internals, may p erceiv e th e ir cireiun- s ta n ccs and e x p e rie n ce s to b e a c o n s e q u e n ce o f th eir own a ction s and w ill th erefore b e lie v e that they can con trol it, w h e re a s o th e rs, the s o -c a lle d extern als, will regard even ts in th e ir lives to b e u nrelated to th eir a ction s and th erefore b eyon d c o n tr o l.14 T h e fact that a p a rth eid legislation h a s in flu enced the en viron m en t in w h ich T in * ) ungium Univeriol oppi'culion Tinaa ocwporij 15a & 30g Prophylactic Tinea cofporis Tinea pedis I. 051. B’MSAAuguH 19951 2. N0T1 Jun* tS>95 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) p e o p le lived, th e job s and level o f ed u ca tio n th ey o b ta in ed and h ealth care w h ich they re ceiv ed , m ay In deed have ca u sed disa d va n ta ged in d ivid u als 10 b eliev e that th eir quality o f life cannot be im p roved th rou gh th e ir own efforts. In d iv id u a ls w h o a ssu m e I hat they have little or 110 con trol over th e ir living en viron m en t or that they lack the n ecessa ry sk ills and k n ow led g e (s e lf-c flic a c v ) to im prove th e ir health may (lm s be d is in clin e d to (rv. ll is 1101 su rp risin g that th ese in d ivid u a ls (ex tern a ls) ex p e rie n ce ill-h ea lth as m ore d e b ilita tin g and strcssfid than internals w h o b elieve that they etui con trol th eir h e a lt h .14 H ow ever, p ro p o n e n ls o f em a n cip a tory health e d u c a ­ t i o n ''" ' ca u tion ed dial m ovem en t s p e c ia lis ts n eed lo m ove b ey on d th e in d iv id u a listic p e rce p tio n o f h ealth b eh a v iou r w h ich ciu re n tly c h a r a c te r is e s h ea lth -rela ted p h ysical activity p rog ra m m es. 1( is in d e e d s iin p lis (ic to view health beh a v iou r a s a m atter o f individual re s p o n ­ sib ility and con trol only, without a ck n o w le d g in g the im pact ol (lie socia l and en viron m en tal variables cited above. T h is redu ction ist id e o lo g y sh o u ld be rejected as it cou ld p rolifera te stereoty p in g o f in d ivid u a ls w h o arc unable to m od ify th eir h ealth risk bcluivioiu- as w eak, lazy, lacking w ill-pow er, se lf-d is c ip lin e or m otiv a tio n .IS A cco rd in g to B andura’s socia l-co g n itiv e theory, social or en viron m en tal factors su ch as s o c io -e c o n o m ic c ir ­ cu m sta n ce s and so cia l rela tio n sh ip s interact in a r e c ip ­ rocal m an n er w ith p sy ch o lo g ica l traits su ch as attitu de and m o tiv a tio n . S im ila rly , a c t io n s an d c o g n it io n s (b e lie fs ) are interactive b eh a viou ra l variables. It can th e re fo re be d e d u c e d that th e so cia l netw ork s w h ich exist w ithin a com m u n ity can a lso in flu ence the h ealth - s e e k in g beh a v iou r o f an in d ividual. G c c r t s c n 17 and R itte r1'' rem in d e d us that the so c io -c id tiu a l p e rce p tio n s about h ealth w h ich a rc d e m o n s tra te d by significant o th e rs in the social n etw ork, may p ersu a d e or d issu a d e an in dividual to adopt h e a lth -p ro m o tin g bchaviom \ T he d y n a m ics w ith in the g rou p as w ell as the in d iv id u a ls’ position with the grou p (su p e rio r o r in ferior) will o f cou rse a lso plav a role. R itte r 1" rep orted that " ... a lack of ties may itscll be a sou rec of stre ss, cre a te d bv not having su fficien t socia l tics to p rov id e for intim acy, o r a se n se of b e lon g in g , and the op p ortu n ity to p rov id e as w ell as receive n u rliira u cc'’ . T h e s e p sy ch o lo g ica l factors arc lik ely to im pact negatively 011 tlie h e a lth -se e k in g b eh a v iou r ol m ost s e cto rs o f the b la ck com m u n ity w h o d o not have a c c e s s to ad eq u a te gym n asiu m , recreation and sp orts fa cilities w ithin th eir resid en tia l areas and su b seq u en tly p articipate in le ss su p p ortive socia l n et­ w ork s ou tsid e th eir co m m m iitics. B andura h y p o th e s iz e d that b e h a v io u r co u ld b e a cq u ired by o b se rv in g role m o d e ls . H ow ever, w hite South .Vfricans g en erally d om in a te the fitness, r e c r e ­ ation and sport d o m a in s mid b la ck s w h o have been c o n ­ d itio n e d to p c r c e iv c th e m se lv e s as an in ferior race, may find it d ifficu lt to identify w ith o r em u la te w h ite role m o d e ls . N egative se lf-e ffica cy th ou g h ts may in fact d i s ­ cou rage b la ck s from en gagin g in a ctiv ities w h ich have tradition ally b een p ra ctised by w h ite s, re g a rd le s s o f its h ealth p ro m o tiv c poten tial. A lie n 1-' intim ated that low se lf-e ffica cy can be b o o s te d by p erson al p erform a n ce a cco m p lish m e n t or p ositive v ica rio u s e x p e rie n ce s, p a r­ ticularly w hen the in h ib ited b eh a v iou rs arc p erform ed by in d ivid u a ls w h o e x p e rie n ce d sim ila r fears and s e lf­ d oubt. W ankel1" a lso o b s e rv e d that feelin g s o f c o m p e ­ tence, c h o ic e an d p e rce iv e d co n tro l tran slates into enjoym ent and intrinsic m otivation and that th is in tim i co u ld foster e x e rcis e a d h e r e n c e , positive adjustm ent and overall w ell-bein g. T h e critica l con trib u tion o f sport d e v elop m en t p ro g ra m m e s in th is regard is obviou s, but th e need to p ro m o te a b r o a d e r range o f p h ysical a ctiv i­ ties am on gst co m m u n itie s w h o are not involved with m ainstream sport (eg. o ld e r ad u lts) sh o u ld not be d is ­ rega rd ed . S o c io -e c o n o m ic c ir c u m s ta n c e s la rg ely d e te r m in e w h e th e r p e o p le have a c c e s s to h ea lth care fa cilities and s e rv ice s and w h e th e r they will b e m otivated to adopt h e a lth -se e k in g behaviour. M aslow ’s h iera rch y o f n e e d s’4 p ostu la tes that th e b eh a v iou r o f in d iv id u a ls is d e t e r ­ m in ed by th eir n e e d s w h ich in turn a rc d e fin e d by b e lie fs. It can b e a s s u m e d that th e beh a v iou r o f in d i­ vid u a ls w h o have a low s o c io -e c o n o m ic statu s w ill, to a large extent, be in flu en ced by p h y sio lo g ica l and safety n e e d s. M ore affluent in d ivid u als w h o arc able to fulfill b a sic n e e d s su ch as nutrition and safety, will prob a b ly b e driven by e ste e m and self-a ctu a liza tion n eed s. A siu - vey c o n d u cte d in 1 989"' revealed that 52,7% o f A fricans, 28,1% o f C o lo u re d s, 10,7% o f In dian s and f,6 % o f W h ites live b e lo w the so -ca lle d b re a d lin e . It can th e re ­ fore be a ssu m ed that a sm a ller percen ta g e o f the b lack com m u n ity will be en cou raged to pa rticip a te in ph vsical activity in o r d e r to look or feel g o o d , w h ile it appears to be a m ajor incentive am ongst w h ite s or m ore affluent in dividuals. D u da and A llis o ir " ex p re sse d co n ce rn about the lack o f cross-cu ltu ra l mial vsis in E xcreisc and S p o il S cie n ce . T h e y c a u tio n e d that d iffe r e n c e s w h ich m av exist betw een w h ite s mid b la c k s with regard to the p e r fo r ­ m ance and p refe re n ce o f p h ysical activity cm inot n e c e s ­ sarily b e attrib u ted to b io lo g ica l and p h ysica l c h a r a c ­ teristics as th ese exp la n a tion s d o not account for intcr- an d -in tragrou p d iffe re n ce s. In stea d , they p ro p o s e d that e x e rcise s cie n tists s lio id d analyse the im pact o f s o c io ­ logical p r o c e s s e s s u ch as socia liza tion d iffe r e n c e s and stereotypica l rein forcem ent o f certain s k ills and b e h a v ­ iour, as w ell as p sy ch o lo g ica l p r o c e s s e s su ch as m otiva­ tion, e x p e cta tio n s or p e rce iv e d ability, from a c r o s s -c u l­ tural p ersp e ctive . T h e ir su g g estion that th e e x e rcise fraternity only a ck n o w le d g e s the cu ltu re of w h ite m ain ­ stream p a rticip a n ts is su p p orted by C o lq id io u n 15 w h o o b se rv e d that the m e d ia p r o m o te s W estern values w h ich a ssocia te m e s o m o r p h ic im a g es w ith a c h ie v e ­ m en t, d y n a m ism , d is c ip lin e , con form ity , efficien cy , “ m a id in e s s ” and fem ininity; e cto m o rp h y with w ea k ­ n ess, m alad ju stm en t, u c m o tic is m , an ti-social te n d e n ­ c ie s , im a ttra ctiven css and co ld n e s s ; and e n d o m o rp h y w ith laziness, in efficien cy, s e lf-in d u lg e n ce , u n h e a lth i­ n ess and im attractiven css. It s h o u ld b e a ck n ow led g ed that th e se p e rce p tio n s are not n ecessa rily su p p orted bv all cultural g rou p s, and th at som e co n u n iu iitics may be less in spired to ch a n g e th eir life-styles in o r d e r to attain th e p re su m e d id ea l im ages o f h ealth and attrac­ tiveness. W om en are apparently very su sce p tib le to p ressu re from s o c ie ty and th e m e d ia to en n d a te im a g e s o f the ideal w om an w h o is d e p ic te d a s th in , active and fit. T h ey are th e re fo re c o e r c e d to re d u ce w eigh t, often lea d in g to bu lim ia and anorexia nervosa. T h e im pact o f g e n d e r stereotypin g is a lso d e m o n stra te d in o th er a sp e cts o f health behaviour. T h e fact that m ost s o c i­ e tie s frow n upon w om en w h o abu se a lco h o l or sm ok e, and g en erally a sso cia te th ese b eh a v iou rs w ith “ m a n li­ n e s s ” , m ay accou n t for the h ig h e r in cid e n ce o f th ese risk-taking b eh a v iou rs am on gst m en. H ow ever, m en arc m ore likely to engage in ph ysical and recreational activ­ SPORTS MEDICINE MARCH 1996 31 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 2. ) ity due to the fact that they generally have less child­ care or domestic responsibilities.21 Women nevertheless demonstrate more concern about health as they are generally responsible for the health care of the family. They are also more dependent on medical care due to their complex and demanding reproductive functions. Duncan, Duncan and McAuley22 identified that social integration or network support appears to enhance exercise compliance amongst men, while attachment and emotional support as well as reassurance of worth motivate women to persist with exercise. It could be expected that individuals’ level of educa­ tion will impact on their health behaviour. However, Bailey and Macphee23 observed that people who have the necessary knowledge about the repercussions of health-risk behaviour will not necessarily be dissuaded from engaging in it. According to the so-called Health Belief Model, people will only be prepared to modify their lifestyles if they perceive themselves to be at risk. The Self-Regulation Model contends that individuals’ responses are determined by their understanding and personal experience ol health problems. These reasons were nevertheless found to be poor motivators to exer­ cise, and it is believed that knowledge of the positive outcomes of regular physical activity, rather than infor­ mation about future health risks, may be greater incen­ tives to exercise. T h is observation concurs with Bandura’s social cognitive theory which hypothesizes that “ ... the perception that physical activity will lead to a valued outcome will motivate individuals to partici­ pate” .13 In conclusion, Exercise Scientists are urged to adopt a multi-factorial and trans-cultural orientation to pro­ motive health care. Schlebusch’s 11 admonition that health-risk behaviour and unhealthy lifestyles are almost intractable in developing communities and that concentrated efforts are required to facilitate change, should serve as a challenge for Exercise Scientists who wish to contribute to the reconstruction and develop­ ment o f their communities. A t issue is the accommodation of health profession­ al roles and the structure of the health care system to a h a nging knowledge base that incorporates culture and social process as important influences upon health behaviour.24 T he social-cognitive theory outlined in this paper is not the only framework which can be used to analyze human thoughts and actions, but it can nevertheless serve as a useful guide to predict variations and consis­ tencies regarding participation in health-promotive physical activity in post-apartheid South Africa. However, additional research on the impact of the aforementioned variables is essential to ensure that physical activity programmes which are aimed at com ­ munity-based health promotion are relevant and sus­ tainable. REFERENCES 1. Steyn, K , Fourie, J. & Bradshaw, D. (1992). The Impact o f chronic diseases o f lifestyle and their major risk factors on mor­ tality in South Africa. South African Medical Journal, Vol 82, October: 227-231. 2. 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