People who engage in regular physical activity are less likely to catch Covid-19 and develop a severe form, concludes a study published on Tuesday August 23, which however has many limitations. “Regular physical activity is associated with a lower risk of infection” to the coronavirus, as well as a better prognosis for “hospitalizations, severity and mortality”concludes this study published in the British Journal of Sports Medicine.
It is already well established that good physical activity promotes a better response of the body to respiratory diseases in general, but this work has focused more specifically on Covid. This is not an isolated study, but an analysis that takes up and compiles around fifteen pre-existing works, which gives it a priori greater solidity. The authors conclude that in the event of regular activity the risk of infection is slightly reduced and, above all, that that of hospitalization decreases by around a third (-36%) and that of death by almost half (- 43%). The authors estimate that you need at least 150 minutes of moderate activity, or 75 minutes of vigorous activity, per week for maximum effect.
However, this type of study does not allow conclusions to be drawn on the mechanisms at work. It is likely that good physical activity directly facilitates an effective immune response, as the authors point out. But it can also limit upstream certain risk factors of a serious Covid, such as overweight. Above all, the authors caution that their conclusions must be taken “with caution” because the studies included vary greatly in their methodology. Most of this work, moreover, is based on the indications given by the patients themselves on their physical activity, and not on an objective assessment.
Finally, the researchers do not exclude a bias that would lead to publishing only the most conclusive studies as to a positive effect of physical activity. But “our findings could guide doctors and health authorities” as to the degree of physical activity to recommend, in particular for patients at high risk of severe Covid, the authors conclude.