How This Pandemic Can Make You Healthier Part 2: Exercise and the immune system

This second part of the series explores how physical activity can boost immune function.

Although exercise has been seen to promote general health for centuries, an appreciation of its potent effect on the body’s defense system is recent. 90% of papers in the field of exercise immunology were published after 1990. Ironically, early publications described an association between the heavy exertion of professional athletes and transient immune dysfunction, the so-called open window hypothesis. These observations have been challenged in recent years. Only in the last decade have we begun to appreciate the positive effects regular exercise has on the immune system.

So how does exercise enhance immune function?

Physical activity increases blood flow. This delivers white blood cells (WBC), the immune cells that track down and destroy infections, more effectively throughout the body. With increased circulation and tissue penetration, infectious agents can be detected and neutralized earlier.

One of the best ways to assess immune competence is by observing the response to an infectious challenge. Vaccination protocols are often used in experimental situations to do such testing. Numerous studies have documented an enhanced immune response in…