American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 17 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE ANTHROPOMETRICS AND PHYSIOLOGICAL DETERMINANTS AS PREDICTORS OF MILITARY SPECIFI SKILLS 1Horst Michael Stocker, 2Thomas Johann Huber, 3Andreas Peter Hofer 1American philosopher, Marjorie Guttag Professor of Ethics and Political Philosophy at Syracuse University 2Ph.D. Physics, Gustavus Adolphus College, University of Wyoming 3Universität Konstanz Abstract: The military has undergone significant changes in recent years, and these changes have had an impact on the selection process for new recruits. In particular, there is now less tolerance for poor physical fitness, as weak fitness can lead to sickness absence and overuse injuries. To identify recruits with the appropriate potential for a military career, common fitness tests are used, but the relationship between these tests and job performance is not always clear. This study investigated the correlations between common fitness tests and simulated basic military tasks. Keywords: Military fitness, Common fitness tests, Simulated basic military tasks Job performance, Physical fitness, Sickness, absence, Overuse injuries Introduction Many changes in the society have had major effects on the role of the military of today. New health standards, changes of motoric and physiological capabilities of children and young adults [22] have impact on the selection process of required personnel [9]. In the course of history, different criteria have been used to determine who would be selected to enter military as professional soldier. As a consequence, there is less tolerance for poor performance in strength, coordination and endurance [16] for a further military career [20]. Weak physical fitness in case of overweight and inactivity has influence on sickness absence [1]and overuse injuries [13] during training [23]. To identify the appropriate potential for a cadre function common fitness tests were used but relationship to job performance was not always clear. In previous researches [21] several tasks were defined which are common for all soldiers as basic skills to perform [10]. According to NATO research manual movement of equipment along a surface, repeated lifting equipment on/ off ground or vehicle, carry various equipment items over distances, move fast- with or without change of direction for short distances, crawl in high and low techniques and march with load were considered as military basic tasks in this research study[17]. The aim of the study was to investigate the correlations between common fitness tests and simulated basic military tasks. 1. Material & methods 53 male officer cadets were recruited for this study. Each of them attends a three-year academic military leadership degree program at the Theresian Military Academy in Wiener Neustadt, Austria. In this educational program daily physical fitness and activities are of great importance in order to ensure adequate fitness for military tasks/operations as well as for a healthy and balanced lifestyle. mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 18 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE The evaluation and assessment of a standardized physical testing battery is approached since multiple years. This testing procedure involves: • 2400m running test • One repetition maximum test • Loaded military march • Military Specific Test 2400m Running Test The selected distance was applied to the Cooper Test concept which is an often-used method to quantify aerobic fitness in military research. The test was performed on a 400m running track, with a 15min individual warm up program. The officer cadets were registered with a bib number in order to ensure accurate lap count and timing. The subjects were sent off in a 5 second countdown and each of them was asked to perform maximum exertion at each stage of the test. In order to exclude a learning effect, participants performed two recognitional trials prior to the intervention. One repetition maximum test One repetition maximum One repetition maximum (1RM) was assessed on a machine based multi rowing machine (see figure 1 below). Leg press (LP), seated bench press (SBP) and seated bench pull (SR) were the selected exercises. Figure 1: Concept 2 Dyno see Concept 2 Training Guide Loaded March and Military Specific Test Military specific skills involved a 3.200m march in full military equipment (Battle dress with weapon AUG77 ) carrying 25kg load. The goal was to finish the 3.200m on selective terrain in the fastest possible time for each individual. The second part is the military specific test (MST), which includes four sections (see figure below). Total time as well as split times were recorded. Section A: Moving in selective terrain includes change in direction, speed and position over a total distance of 140m including 10m of crawling. Section B: Load pulling of 50kg over a total distance of 40m Section C: Load carrying of 2x18kg over a total distance of 100m.(exercise farmer’s walk) Section D: Load lifting / releasing of 5x24kg on a 125cm high box (exercise dead lift) mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 19 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE Figure 2: Military Specific Test 2.1. Data analysis Split times of military basic tasks, 2400m running test and loaded march were recorded with a manual timing system (Hanhart Modul 3, Hanhart 1882 GmbH, Gütenbach, Germany). One repetition maximum (1RM) for leg press (LB), seated bench press (SBP) and seated bench pull (SR) were performed on a machine based multi rowing machine (Concept 2 Dyno, Concept 2 Ltd, UK). In a further step second by second data and 1RM values were prepared in Microsoft Excel (Windows 10, Microsoft Windows, Washington, US) for statistical calculations. Relative O2max values were derived from the 2400m distance running time using following equation according to the Cooper test [4]. 3.5 + A further formula derived O2max from 2400m running time was applied to compare the original Cooper based results with the new approach. However, the new approach indicated a higher standard deviation and coefficient of variation compared to the traditional method [13], so the cooper formula was selected for O2max estimation. 2.2. Statistics using Shapiro Wilk (p>0.05). Correlation and multi regression analyses were conducted to compare the relationship between strength and endurance parameters on the soldier’s occupational tasks. All statistical analyses were generated using the SPSS statistics 20 software package (IBM Corporation, Armonk, New York). mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 20 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE 3.Results 3.1. Subjects The officer cadets (N = 53, Age: 24.6 ± 4.6 years) average of maximum oxygen consumption ( O2max) of 53.74 ml min-1 kg-1 during the 2400m distance running test to maximal exertion. The subject’s anthropometric and physiological characteristics are listed in the table below. Table 1: Descriptive statistics of the physiological and anthropometric profile (mean ± SD; 95 % CI confidence interval). Age [Years] 24.6 ± 4.6 23.3 – 25.9 Height [m] 1.80 ± 0.6 1.78 – 1.81 Body mass [kg] 77.2 ± 9.3 74.6 – 79.8 BMI = body mass index, V̇O2 = maximum oxygen consumption 3.2. Physical Performance Tests For cardiorespiratory fitness a standardized 2400m running test was performed on a track to assess endurance performance. Regarding strength testing push-ups, leg press, bench press and bench pull were performed on a concept. In table 2 physical performance parameters are presented. Table 2:Descriptive statistics of the physical performance tests (mean ± SD; 95 % confidence interval). Variables Mean ± SD N = 53 95 % CI N = 53 2400m Test [mm:ss] 09:37 ± 34 [s] 09:26 – 09:46 Military Specific Test [mm:ss] 02:15 ± 35 [s] 02:04 – 02:25 Military March [mm:ss] 19:40 ± 02:02 19:04 – 20:16 Push-Up [reps] 40 ± 9 37 – 43 Leg press [kg] 264 ± 41 251 – 277 Seated Bench Press [kg] 98 ± 16 93 – 104 Seated Bench Pull [kg] 103 ± 17 97 – 109 3.2.Military Specific Test Military basic skills were assessed with a military specific test as described above. Participants had to complete all four sections in one run (see table below). Table 3: Descriptive statistics of the occupational tasks (mean ± SD; 95 % confidence interval). Variables Mean ± SD N = 53 95 % CI N = 53 Total [mm:ss] 02:15 ± 35 [s] 02:04 – 02:25 Station A [s] 55.7 ± 4.7 54.38 – 57.07 Station B [s] 24.4 ± 3.7 23.3 – 25.4 Station C [s] 45.3 ± 7.0 43.3 – 47.3 Variables Mean ± SD N = 53 95 % CI N = 53 BMI 24.1 ± 2.2 23.4 – 24.7 relative V O max 2 ml [ min - 1 kg - 1 ] 53.74 ± 3.0 52.8 – 54.5 mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 21 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE Station D [s] 15.1 ± 10.1 – 18.0 3.3 .Influence of anthropometrics on physical performance Pearson’s linear correlation was used to investigate the effects of anthropometric parameters height, body mass and body mass index (BMI) on the 2400m running test (see table 4). No significant relationship was found between height (r = -0.199, p = 0.142), body mass (r = -0.008, p = 0.548) and BMI (r = 0.057, p = 0.677) on 2400 m running time. Derived O2max of the 2400m running test however significantly correlated with BMI (r = -0.285, p = 0.033). Regarding strength parameters LP, SBP, and SR no significant relationship was found for body mass (p > 0.05). BMI significantly influenced LP (r = 0.389, p = 0.004), SBP (r = 0.710, p = 0.001) and SR (r = 0.570, p = 0.001). In addition, height significantly correlated with the LP (r = 0.349, p = 0.010). A multi linear regression analysis compared the influence of anthropometrics on strength parameters and showed a significant influence on the LP (F(3,49) = 6.173, p = 0.001) with a R2 of 25.3% explained variance. Height (p = 0.004) and BMI (p = 0.001) demonstrated a significant influence on the LP. Table 4: Pearson correlation coefficient on anthropometrics and physiological determinants Leg Press [kg] -0.70 0.621 0.34 0.010* 0.38 0.004 0.12 0.360 Seated Bench Press [kg] -0.43 0.762 0.19 0.157 0.71 0.001* -0.05 0.969 Seated Bench Pull [kg] -0.22 0.887 0.13 0.376 0.57 0.001* -0.00 0.969 2400m running [mm:ss] -0.00 0.952 0.19 0.142 0.57 0.677 -0.22 0.104 Military march [mm:ss] -0.21 0.114 0.45 0.743 0.53 0.699 -0.42 0.001* Military Specific Test -0.25 0.61 -0.14 0.287 0.10 0.941 -0.34 0.010* [mm:ss] BM = body mass, BMI = body mass index, O2max = relative maximum oxygen uptake, *significant relationship 3.4. Influence of physical performance on military specific skills Linear correlation according to Pearson compared the influence of physical performance parameters including 2400m running test, LP, SBP and SR on BM [kg] Height [cm] BMI O max 2 ] ml/min/kg [ r p r p r p r p mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 22 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE the soldier cadet’s military specific skills including the MST and As the results of this study indicate aerobic performance is a strong determinant of military specific skills. In contrary 1RM of LP, SBP and SR did not show a statistically significant relationship with the MST and military walk. The subjects in this study were classified as moderately trained according to the aerobic determinants [15] with small variations in weight and BMI. These findings are in contrast to other studies in military research, where large effects have been reported in the relationship of anthropometric and physical determinants [18]. In addition, the influence of anthropometrics on physical performance is often associated to lean body mass [19] predominantly in studies with large heterogeneity. The collective homogeneity in this study is probably due to pre selection criteria for officer cadets while other research is mainly based on cross sectional data from soldiers in military basic training to special forces [6]. Muscular strength has shown to be related to military specific skills in the literatur. Especially muscular endurance ability has been named frequently as a greater predictor for military fitness than 1RM [3]. These findings are in line to our observations, as 1RM of upper and lower extremities did not show a significant relationship to neither general physical performance nor military specific skills. Cardiorespiratory fitness in general and military population is known to be an important aspect for both, health and performance. Due to that reason, many military fitness test batteries consist of minimum one cardiorespiratory fitness assessment. The most commonly used methods in the literature are capacity tests in form of fixed distance or duration among 1.5-3km or 8-12min in order to reach O2max [8]. As an alternative, shuttle runs can be performed depending on the available material and group size. The approach in this study for assessing cardiorespiratory fitness was based on current military research recommendations. In this study, a close military march (see table 4). Strength para meters did not correlate significantly with the MST and military march (p > in 0.005) . However as shown Table 4 below, O max 2 derived from the 2400 m running test showed a significant relationship with total time in the MST (r = - = 0.010 0.340 , p as well as all split times (p < 0.05). Furthermore ) O 2 max was found to have a significant effect on the military march (r = - 0.428 , p = 0.001) see Figure 2 . Figure 2 : Relationship of O 2 max and military walk 4 . Discussion mailto:topacademicjournals@gmail.com American Journal of Medical and Physical Education Vol.7, Issue 3; May-June 2022; 1252 Columbia Rd NW, Washington DC, United States https://topjournals.org/index.php/AJMPE; mail: topacademicjournals@gmail.com 23 | A m e r i c a n J o u r n a l o f M e d i c a l a n d P h y s i c a l E d u c a t i o n | https://topjournals.org/index.php/AJMPE interaction of 2400m running performance to military specific skills as well as to the military march can be confirmed. These findings support that aerobic performance might have a larger influence on military performance than 1RM, which is also confirmed by other research findings [11]. One limitation of this study is that O2max values of the 2400m running test have not been measured directly with a breath-by-breath spiro-ergometry system. This could lead to under- or overestimation of real O2max for an individual [2]. Nevertheless, applying the Cooper formula in large cohorts [5] like the military has been a frequently used method, which was one of the reasons why O2max in this study was derived from 2400m running time [12]. 5. Conclusions The results indicate that the endurance determinants predominantly influence the military specific skills more than the 1RM. In addition, these findings underpin the importance of a high level of muscular endurance for MST and the military march [13]. Anthropometric characteristics have demonstrated to influence both strength [18] and endurance components [5]. 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