Leukocyte mitochondria alterations after aerobic exercise in trained human subjects.

Abstract

Exercise is associated with intensity-dependent immune disturbances. Leukocyte mitochondrial alterations and apoptosis may contribute to this phenomenon. To investigate the effects of different intensities of aerobic exercise (AE) on leukocyte mitochondrial transmembrane potential (MTP) and the propensity of apoptosis. Blood samples were collected from 12 subjects who performed AE for 3 consecutive days (35% maximal oxygen consumption (VO2max)). Leukocyte MTP and apoptosis were measured by flow cytometry. The subjects performed two additional sessions of AE of higher intensities (60% and 85% VO2max) with an intervening 4-wk washout period. The measurements were repeated during each session. Leukocyte MTP declined during daily, repetitive AE at an intensity of 60% and 85% VO2max. Similar changes were not found during a more moderate AE (35% VO2max). Leukocytes increased their propensity of apoptosis a period (3-5 d) after the start of the AE. High-intensity AE has accumulative effects on the mitochondrial energization status and vitality of peripheral blood leukocytes. Leukocyte MTP is a potentially applicable indicator for monitoring immune distress due to overtraining.