Several studies have shown that exercise has either a positive or a negative effect on immunity. These effects depend on the nature, intensity and duration of exercise.
Individuals engaging in moderate physical activity are at lower risk of illness compared with sedentary individuals. Conversely, excessive volumes of strenuous endurance exercise may suppress immune function, thereby increasing the risk of illness. For example, in one of the clinical trials, a five-fold increase in risk of infection was observed in the 2 weeks following a competitive ultra-endurance running event.
Heavy training schedules or endurance competitions such as marathons or long-distance cycling are examples of extreme physical stress and can lead to depression of immune system in athletes, which is associated with increased susceptibility to infection especially upper respiratory tract infections.
In general, post-exercise immune function impairment is highest when the exercise is continuous, prolonged (>1.5 hours), of moderate to high intensity (70% to 77% maximum oxygen uptake (VO2 max)) and performed without food intake.
One possible means to reduce infection risk is to use appropriate immune-nutritional support. Various nutritional agents have been tested for their capacity to attenuate immune changes and inflammation following intensive exercise.
Example of immune supporting nutrients are echinacea, glutamine, Omega-3, cystine, theanine, resveratrol, lactoferrin, quercetin and many more.
If you are not sure whether you are receiving essential nutrients through diet, please CONSULT our dietitian who will design diet program which is suitable to your lifestyle.
Acute Effects of Exercise on Immunity by Carlo Giammattei, Riccardo Banducci, Giulia Pierami and Alberto Tomasi, Aspetar Sports Medicine Journal.