How does physical activity affect immune health?

Current research suggests that when it comes to exercise for immune health, moderation, balance, and consistency are key. Moderate exercise has been shown to have numerous benefits on immune health. Although physical activity is a stressor that does incite an immune response, the degree of the immune response and whether it’s harmful or helpful to immune health can be situationally dependent.

The current understanding is that consistent, moderate to vigorous intensity exercise (<60 minutes in length) is beneficial for immune health and can enhance adaptive immunity, thereby improving protection from community acquired illness and increasing the efficacy of vaccines.^[1][2] Muscle contraction is also beneficial to immune health by releasing helpful immune mediators, aiding in lymphatic drainage of waste products, and possibly even diversifying the gut microbiome.^[3][4] On the other hand, extreme exercise (especially in the untrained) can be detrimental to immune health. When healing from extreme exercise, the immune system becomes preoccupied and can devote fewer resources to defense.^[5]