How much sport is too much? A focus on musculoskeletal health of the adult

A large body of research has shown that physical activity has a positive effect on physical and mental health [1, 2]. In particular, regular aerobic and resistance training is associated with a reduced risk of cardiovascular morbidity, cancer, neuro-degenerative diseases and mortality. Updated World Health Organization (WHO) recommendations for 2020 emphasize that adults should engage in at least between 150 and 300 min/week of moderate-intensity aerobic activity or at least between 75 and 150 min/week of vigorous-intensity aerobic activity, or an equivalent combination. In addition, adults aged 65 years and over should engage in complementary muscle-strengthening and body-balancing activities on two or more days a week. The four domains of physical activity are work, active transport, household and leisure. Sport, a type of leisure-time physical activity, has been shown to improve cardiorespiratory fitness, physical function and mental health in people aged 60 and over in a recent meta-analysis of randomised controlled trials (RCTs) [3]. However, the WHO does not clearly recommend upper limits for the intensity and amount of physical activity. However, the health effects of exercise volumes beyond the "optimal dose" are currently under debate. Of course, some cases of sudden death have been reported in athletes under 40 years of age, usually due to a prevalent heart defect, but also in athletes over 40 years of age, mainly due to acquired atherosclerotic coronary disease. However, it was not directly related to the intensity and amount of physical * Olivier Bruyère