The Immune System

Abstract

Although there have been many studies on exercise and the immune system response, information collected is little about on its linkage to illness. Moderate exercise has been related with a one-third decrement in the occurrence of upper respiratory tract infections (URTI). It also reduces the risk of infection and increases other immunological variables, compared with a sedentary individual. In addition, epidemiological evidence suggests that moderate exercise has a beneficial effect on the human immune system, while extreme exercise impairs it, an effect which is modeled in a J curve. Nonetheless, elite athletes following a very prolonged and intensive exercise bouts for long-lasting training times, or participation in a very demanding sports events, increase the risk of infection. In marathon runners, it has been found that their long-lasting prolonged high-intensity exercise bout was related with an increased risk of an infection, although others did not find that result. All-out strenuous exercise during continuing infection and fever may be risky and should always be avoided. Because myocarditis may or may not be accompanied by fever, athletes should be informed about the symptoms advice of this dangerous condition. In athletes, pulmonary dysfunction and illness are common during competitions events, which weakens significantly physical performance. Long-lasting vigorous exercise training affects white blood cell, which results in a decreased host protection, during which viruses and bacteria can gain a grip, thus developing an infection. Other factors such as psychological stress, lack of sleep, and malnutrition can also depress immunity and lead to the increased risk of infection. Inadequate recovery time between training sessions leads to an impermanent condition of immunological depression. This condition is reversible if the athlete takes a few days of rest.