The Effects of Physical Exercise on the Immune System

Physical activity and abnormal environments cause changes in the functioning of the immune system. The aim of this study was to compare the effect of exercise in cold, hot and normal temperature conditions on the number of leukocytes and platelets in athletes’ blood. In this clinical trial study, 10 young male endurance athletes performed the same exercise for one hour with 60% of maximum oxygen consumption in three natural, cold and warm environments. Before, immediately and two hours after exercise, neutrophils, L Monocytes and platelets were counted. Data were analyzed using repeated measures statistical test and Bonferron post hoc test. The total number of leukocytes increased significantly in all three environments after exercise (p <0.0001), but neutrophils did not increase significantly only in warm environment and lymphocytes did not increase significantly in cold environment (p <0.05). Lymphocytes in cold, normal and warm environment had a significant decrease (p <0.05), but the decrease in leukocytes was not significant except in neutrophils in hot environment (p <0.05). Exercise excitability in different temperature environments stimulates and accumulates immune cells. However, exercise in warm environments further increases the amount of these cells and also delays the recovery of the immune system to a resting state after exercise.