Physiology and biochemistry: influence of exercise on phagocytosis

Phagocytic cells constitute the organism's first line of defence against external aggression. These cells carry out their non-specific defence function through what is known as the phagocytic process. This can be split up into several stages: adherence, chemotaxis, attachment, ingestion and killing of the foreign agent. The influence of exercise on the phagocytic process is dependent on the step considered, but in general, different responses have been observed in the adherence and chemotaxis capacities depending both on the intensity of exercise and on the phagocyte (neutrophil or monocyte-macrophage) studied. However, with respect to the attachment and ingestion of antigen, exercise generally induces an increase in every "situation", independent of the intensity of physical activity and the involvement of neutrophils or macrophages. The results with regard to the microbicide capacity that have been obtained up to the present time are very contradictory, showing perhaps a greater dependence on the phagocyte studied and on the intensity of exercise. This fact may be due to different methods used in the studies. One could conclude that exercise stimulates certain stages of the phagocytic process. This stimulation could counterbalance the decreased lymphoid activity after certain types of exercise that some authors have reported.