Layout 1 “Home Gym-Bed” exercises and sarcopenia Eur J Transl Myol 34 (3) 12901, 2024 doi: 10.4081/ejtm.2024.12901 I was interested to read the article by Quadrelli et al. on a study on the prevention of sarcopenia using daily “home Gym-Bed” training for 30 minutes per day over 10 years in a 70-year-old man who was examined using 3D CT imaging.1 It was found that muscle mass did not change over the 10 years despite ageing.1 It was concluded that whole-body exercise in bed can help preserve muscle mass and density in older people,1 and that advanced imaging techniques can quantify the effectiveness of non- pharmacological interventions against sarcopenia.1 The study is excellent, but some points should be discussed. The first point is that muscle mass depends not only on the level of physical activity, but also on various other factors such as the composition of the diet, the balance between sympathetic and parasympathetic tone, genetic background and hormone production. A high testoste- rone level and a low antitestosterone level can promote an increase in muscle mass. In a study of nine subjects who received testosterone enanthate (3 mg/kg per week) for 12 weeks, all nine subjects showed an increase in muscle mass as measured by urinary creatine excretion.2 A high-protein, high-carbohydrate diet compared to a ke- togenic diet can also promote an increase in muscle mass.3 A hypocaloric or low-carbohydrate diet, on the other hand, can promote sarcopenia. There is also ev- idence that a high sympathetic tone can promote an in- crease in muscle mass.4 The second point is that when analyzing muscle mass we must take into account co- morbidities and drugs that can modify muscle mass. Sev- eral chronic diseases (e.g. immunologic diseases, autoimmune diseases, malignancies) are known to be complicated by sarcopenia. The third point is that imag- ing procedures that generate axial images before and after exercise must be performed with the same method at the same level before and after exercise. Since muscle size can change significantly from layer to layer, it is es- sential to standardize the assessment of 3D muscle vol- ume using 3D CT. The fourth point is that the only study in which home whole-body exercise in bed was per- formed in 22 patients found no significant reduction or prevention of sarcopenia through exercise.5 Therefore, it is questionable whether daily or thrice-weekly 30-minute gymnastics in bed really prevents sarcopenia. The fifth point is that sarcopenia is not only a degenerative pro- cess associated with ageing, but can also depend on a person's genetic predisposition. For example, there are a number of neuromuscular diseases that are associated with muscle wasting and have a late onset that can be mistaken for sarcopenia. In such cases, home Gym-Bed may be of little benefit as muscle wasting is an inherent feature of the disease. In summary, this interesting study has limitations that put the results and their interpretation into perspective. Ad- dressing these limitations could strengthen the conclusions and corroborate the study's message. No general conclu- sion about the effect of a therapeutic intervention to pre- vent sarcopenia can be drawn from a single case. The effect of a therapeutic intervention can only be reliably as- sessed by a randomized, double-blind, placebo-controlled, cross-over trial. Until the results of such a study are avail- able, no reliable conclusions can be drawn. Ethical approval Not applicable. Consent to participation Not applicable. Consent for publication Not applicable. Funding None received. Key Words: sarcopenia, exercise, home Gym-Bed, 3D-CT, case report. Eur J Transl Myol 34 (3) 12901, 2024 doi: 10.4081/ejtm.2024.12901 Cohort studies using 3D-CT are needed to assess whether “home Gym-Bed” exercises are beneficial against sarcopenia Josef Finsterer Department of Neurology, Neurology and Neurophysiology Center, Vienna, Austria. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License (CC BY-NC 4.0) which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. - 122 - Non -co mmerc ial us e o nly “Home Gym-Bed” exercises and sarcopenia Eur J Transl Myol 34 (3) 12901, 2024 doi: 10.4081/ejtm.2024.12901 Availability of data and material All data are available from the corresponding author. Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Author contribution: JF was responsible for the design and conception, wrote the first draft, and gave final approval. Corresponding Author Josef Finsterer, Department of Neurology, Neurology and Neurophysiology Center, Postfach 20, 1180 Vienna, Austria. Tel.: +43.1.5861075 – Fax: +43.1.5861075. ORCID ID: 0000-0003-2839-7305 E-mail: fifigs1@yahoo.de References 1 Quadrelli M, Baccaglini T, Morra A. Quantitative 3D- CT imaging of sarcopenia mitigation in the elderly: evidence from a case report. Eur J Transl Myol 2024;34:12715. 2 Griggs RC, Kingston W, Jozefowicz RF, et al. Effect of testosterone on muscle mass and muscle protein synthesis. J Appl Physiol (1985) 1989;66:498-503. 3 Pasiakos SM, Cao JJ, Margolis LM, et al. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized con- trolled trial. FASEB J 2013;27:3837-47. 4 Delbono O, Rodrigues ACZ, Bonilla HJ, Messi ML. The emerging role of the sympathetic nervous system in skeletal muscle motor innervation and sarcopenia. Ageing Res Rev 2021;67:101305. 5 Maccarone MC, Caregnato A, Regazzo G, et al. Ef- fects of the Full-Body in-Bed Gym program on quality of life, pain and risk of sarcopenia in elderly sedentary individuals: preliminary positive results of a Padua prospective observational study. Eur J Transl Myol 2023;33:11780. Disclaimer All claims expressed in this article are solely those of the authors and do not necessarily represent those of their af- filiated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher. Submitted: 4 August 2024. Accepted: 20 September 2024. Early access: 20 September 2024. - 123 - Non -co mmerc ial us e o nly