Does immunity benefit from regular exercise?

It is widely agreed that regular moderate-intensity exercise is beneficial for immunity, but a view held by some is that more arduous exercise can suppress immune function, leading to an ‘open-window’ of heightened infection risk in the hours and days following exercise.

In a study in 2018, this hypothesis was challenged by Dr. Campbell and Dr. Turner. They reported in a review article that the theory was not well supported by scientific evidence, summarizing that there is limited reliable evidence that exercise suppresses immunity, concluding instead that exercise is beneficial for immune function.

They say that, in the short term, exercise can help the immune system find and deal with pathogens, and in the long term, regular exercise slows down changes that happen to the immune system with aging, therefore reducing the risk of infections.

The article concludes that infections are more likely to be linked to inadequate diet, psychological stress, insufficient sleep, travel, and importantly, pathogen exposure at social gathering events like marathons - rather than the act of exercising itself.

Source: https://pubmed.ncbi.nlm.nih.gov/32139352/