Detraining Effects of COVID-19 Pandemic on Physical Fitness, Cytokines, C-Reactive Protein and Immunocytes in Men of Various Age Groups.

Background and Objectives: Since the start of the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus II, levels of physical inactivity have become more severe and widespread than ever before. Physical inactivity is known to have a negative effect on the human body, but the extent to which reduced physical fitness has effected immune function before and after the current pandemic has not yet been uncovered. The aim of this study was to investigate the detraining effects of the COVID-19 confinement period on physical fitness, immunocytes, inflammatory cytokines, and proteins in various age groups. The participants of this study included sixty-four male adults who did not exercise during the pandemic, although they had exercised regularly before. Materials and Methods: Participants were classified by age group, which included the 20s group (20s'G, n = 14), 30s group (30s'G, n = 12), 40s group (40s'G, n = 12), 50s group (50s'G, n = 12), and 60s group (60s'G, n = 14). Results: Regarding body composition, muscle mass significantly decreased, whereas fat mass, fat percentage, and waist/hip ratio significantly increased in most groups. Cardiopulmonary endurance and strength significantly decreased in all groups, while muscle endurance and flexibility decreased in some groups compared to the pre-COVID-19 pandemic. This study confirmed the immunocytopenia and enhanced inflammation due to physical inactivity during the COVID-19 pandemic, and a greater detrimental decrease mainly after the age of 50. Conclusion: This study confirmed a decrease in physical fitness after the start of the COVID-19 pandemic, characterized by an increase in fat mass and a decrease in muscle mass, thereby increasing cytokines and reducing immunocytes in the body. While social distancing is important during the pandemic, maintaining physical fitness should also be a top priority.

Effects of High Intensity Plank Exercise on Physical Fitness and Immunocyte Function in a Middle-Aged Man: A Case Report.

Background and Objectives: Although the plank exercise is difficult to perform for untrained people, it does not require money, special equipment, or much space. However, it is not known how plank exercises affect physical fitness and immunocyte function. This study analyzed the changes in physical fitness and immune cells of a middle-aged man after performing 4 weeks of elbow plank exercise. Materials and Methods: Elbow plank exercise was performed for approximately 20 min (resting time, around 10 min) a day, 5 days a week for 4 weeks. The intensity was checked daily with ratings of perceived exertion (RPE). When the participant reached an intensity of RPE 15, RPE 16, and RPE 17 of the RPE 20 scale, 1 min of rest was given before repeating the process. Results: Compared with the pre-values, (1) all the physical fitness factors (muscle strength, muscle endurance, flexibility, and cardiopulmonary fitness) were increased after 4 weeks; (2) body weight, skeletal muscle mass, and the basal metabolic rate were increased, whereas body fat mass and fat percentage were decreased; and (3) although the variables of complete blood count were changed positively, some were not. Specifically, CD3, CD8, and CD56 were increased, whereas CD4, CD4/CD8, and cytotoxicity were decreased. These results show that elbow plank exercise can improve all factors of physical fitness and improve some of the immunocyte functions of a middle-aged man. Conclusions: This study confirmed that, although the elbow plank exercise of vigorous intensity for 4 weeks improved physical fitness, it was not effective in improving some immunocyte functions. Therefore, the exercise intensity of plank exercises for improving immunocyte functions should be reconsidered.