Is Exercise the Best Medicine during a COVID-19 Pandemic? Comment on Constandt, B.; Thibaut, E.; De Bosscher, V.; Scheerder, J.; Ricour, M.; Willem, A. Exercising in Times of Lockdown: An Analysis of the Impact of COVID-19 on Levels and Patterns of Exercise among Adults in Belgium. Int. J. Environ. Res. Public Health 2020, 17 , 4144

From Constandt et al.’s survey of 13,515 Belgium respondents, regular physical activity can be successfully initiated and sustained during a lockdown, with appropriate social distancing measures. Documentation that 77% of highly active people and 58% of low active people exercised as much or more following the institution of a nationwide lockdown was impressive, given that the cases of COVID-19 were accelerating at that time. The Belgian government’s central promotion of exercise, to boost both the mental and physical health of the population, likely contributed to the health, tolerance, and ultimate success of lockdown. In this commentary, we wish to pose a follow-up query which highlights the potential detrimental effects of intense exercise (competition) performed without social distancing measures. The proposed graphical abstract elucidates these possible risks, in contrast to the favorable results outlined in Constandt et al.’s study.