The Effects of Exercise on Immunity

Key Points Exercise improves health and immunityOvertraining can reduce immunity though and make us more prone to infectionsIt is also important to take in enough total energy (‘fuel’) to preserve and improve immune function along with exercise It is widely accepted that exercise improves health and is, by extension, a valuable contributor to proper immune functioning and resistance to infection. However, excessive exercise is a stressor that can dampen immune functions and as a result, over-training can lead to increased rates of infection with colds and flu-like viruses, a situation commonly seen in athletes. Over-exercise or over-stress from any cause is pro-inflammatory and over half of all sports injuries are also secondary to overuse.1 Markers of antioxidant status such as glutathione concentration and inflammatory markers such as interleukin 10 are affected by long periods of intense training.2 So, exercise helps to mitigate stress and fatigue and helps us to modulate inflammatory/immune and antioxidant pathways, BUT too much (over-reaching) can be just as detrimental as too little. Overreaching and over-training syndrome in athletes is depicted as a continuum, this is also likely to be the case for generalised ‘stress’. So, excessive exercise (or any other stressor) can be thought of as stress, leading to fatigue, leading to a greater incidence of infection (and burnout). Excessive exercise (or any other stressor) can be thought of as stress, leading to fatigue, leading to a greater incidence of infection Moderate amounts of exercise improve immune system functions and reduce the risk of infection. On…