Keeping up with regular exercise is an important way of keeping your immune system healthy, even when stuck at home, according to a study conducted by the University of Bath.1

According to the study, there is a general consensus that regular bouts of short-lasting moderate intensity exercise is beneficial for host immune defense, particularly in older adults and people with chronic diseases.2

In contrast, infection burden is reported to be high among high performance athletes and is second only to injury for the number of training days lost during preparation for major sporting events. This has led to conjecture that strenuous exercise can suppress immunity and increase infection risk, independently of the many other factors experienced by these populations; however, this belief has recently been challenged, according to the study. 2

The objective of the study was to solicit opposing arguments centered around whether exercise affects immune function to increase susceptibility to infection. Issues that were investigated included:
 
  • Whether or not athletes are more susceptible to infection than the general population.
  • Whether exercise is capable of altering immunity to increase infection risk independently of the multiple factors that activate shared immune pathways and are unique to the study populations involved.
  • The usefulness of certain biomarkers and the interpretation of in-vitro and in-vivo data to monitor immune health in those who perform strenuous exercise.
  • The quality of scientific evidence that has been used to substantiate claims for and against the potential negative effects of strenuous exercise on immunity and infection risk.2

A key point of agreement between the study groups included that infection susceptibility has a multifactorial underpinning. However, an issue that remains from the study was whether exercise is a causative factor of increased infection risk in athletes.2

Leading physiologists James Turner, MD, and John Campbell, MD, concluded that infections are more likely to be linked to an inadequate diet, psychological stress, insufficient sleep, travel, and pathogen exposure at social gathering events.

“Our work has concluded that there is very limited evidence for exercise directly increasing the risk of becoming infected with viruses,” Turner said in a press release. “In the context of coronavirus and the conditions we find ourselves in today, the most important consideration is reducing your exposure from other people who may be carrying the virus. But people should not overlook the importance of staying fit, active and healthy during this period. Provided it is carried out in isolation—away from others—then regular, daily exercise will help better maintain the way the immune system works—not suppress it.”

REFERENCES
  1. Regular exercise helps keep the immune system healthy, say University researchers. University of Bath TeamBath. https://www.teambath.com/2020/03/30/regular-exercise-healthy-immune-system/. Published March 30, 2020. Accessed April 3, 2020.
  2. Simpson RJ, Campbell JP, Gleeson M, et al. Can exercise affect immune function to increase susceptibility to infection? Exerc Immunol Rev. 2020; 26: 8-2 https://pubmed.ncbi.nlm.nih.gov/32139352/.