Immune Response to Exercise During Growth.

Two papers were selected for this commentary. The first paper (Citation 1) suggests that a 10-week, moderate-intensity exercise program performed early after allogeneic hematopoietic stem cell transplantation is feasible in this fragile population, and might improve cell cytotoxicity by redistributing subpopulations of NK cells. This study adds to the growing evidence that enhancing immune cell surveillance (e.g., NK cells) in response to exercise could benefit cancer patients. The second paper (Citation 2) studied neutrophil-related mediators of oxidative stress and inflammatory cytokines in response to exercise in children compared with adults. The authors found age/maturation-related differences in these responses. The paper provides a valuable introduction to the current knowledge of maturational changes in immune mediators' response to exercise. Data about leukocyte function in response to exercise in healthy children and in children with clinical conditions is scant. The need for prospective large scale pediatric clinical exercise studies is clear. Molecular approaches to understand the mechanisms through which physical activity can improve health will help to shape guidelines that optimize the mode, frequency, intensity, and duration of the training intervention.