Exercise and the Immune System – Focusing on the Effect of Exercise on Neutrophil Functions

A relationship between intense exercise, leukocytosis and susceptibility to illness was already reported at the beginning of the past century (1-3). Today there is a consensus among researchers and clinicians that exercise have effects on various aspects of the immune function (4). The complexity of the underlying mechanisms and the clinical implications and directions need continuous evaluation. Investigators face challenges associated with immune measures and the interpretation of their changes. They should bear in mind that there is inter-individual variability of the exercise capacity, recovery, stress tolerance and immunocompetence. Short exposure to exercise could promote beneficial and apropriate physiological response of the immune system, while heavy exertion could be detrimental to health. In recent years, the development of advanced laboratory techniques contributed to enrich our knowledge and deepened the understanding of the mechanisms underlying the immune system in sports medicine. The development of fluorescent antibodies techniques allow identifying cell sub-types and receptors. Molecular technology and new cytokine methods of identification have permitted the detection of humoral factors present in the body at low concentrations, for short periods of time and to study the effect of exercise on gene expression profiles (5,6). Studies on recreational and elite athletes should be systematic and well controlled in order to formulate evidence-based guidelines to preserve a balanced immune function.