Comparative effects of integrated physical training with a high protein diet versus a regular protein diet in post-COVID-19 older men with sarcopenia symptoms

Background Sarcopenia has become a significant health issue, particularly as a common consequence of COVID-19 in older adults. Objective This study aimed to explore the clinical and psychological effects of integrated physical training with a high-protein diet compared with a regular protein diet in community-dwelling older men who had recovered from COVID-19 and exhibited symptoms of sarcopenia. Methods This is a single-blinded, randomised, controlled study conducted from March 2020 to December 2023 at the University hospital. The eligible participants were randomly assigned to two groups using the block randomisation method. The first group underwent integrated physical training with a high-protein diet (group A; n=38), with an average age of 64.1±3.8 years, while the second group underwent integrated physical training with a regular protein diet (group B; n=38), with an average age of 64.5±3.6 years over an 8-week period. Clinical parameters (handgrip strength and muscle mass - cross-sectional area CSA) and psychological measures (kinesiophobia and quality of life) were assessed at baseline, the fourth week, the eighth week and at a 6-month follow-up. The data were analysed using a 4×2 mixed model for repeated measures at different time points. Results Demographic characteristics such as age, height, weight and body mass index did not show any statistically significant differences between the groups (p>0.05). After the 8-week intervention and at the 6-month follow-up, handgrip strength decreased by -5.0 (95% CI -6.21 to -3.78), midthigh CSA decreased by -3.7 (95% CI -6.53 to -0.86), midcalf CSA decreased by -4.4 (95% CI -6.80 to -2.00), kinesiophobia level increased by 8.1 (95% CI 7.16 to 9.03) and quality of life decreased by -6.3 (95% CI -9.0 to -3.5). The findings indicated significantly greater improvement (p<0.001) in group A compared with group B, although there was no significant difference in muscle CSA in the arm region (p>0.05). Conclusion Integrated physical training with a high-protein diet led to improvements in clinical (muscle strength and muscle mass) and psychological (kinesiophobia and quality of life) parameters compared with integrated physical training with a regular protein diet in older men recovering from COVID-19 and displaying symptoms of sarcopenia.