Exercise and Immunity

Epidemiological evidence suggests a link between the intensity of the exercise and the oc‐ currence of infections and diseases. The innate immune system appears to respond to chron‐ ic stress of intensive exercise by increased natural killer cell activity and suppressed neutrophil function. The measured effects of exercise on the innate immune system are com‐ plex and depend on several factors: the type of exercise, intensity and duration of exercise, the timing of measurement in relation to the exercise session, the dose and type of immune modulator used to stimulate the cell in vitro or in vivo, and the site of cellular origin. When comparing immune function in trained and non-active persons, the adaptive immune sys‐ tem is largely unaffected by exercise.