Effects of aerobic exercise training on lymphocyte subpopulations

This study was conducted to determine the effects of an aerobic exercise training program on subpopulations of lymphocyte phenotypes. Fourteen healthy but sedentary males, 18-40 years of age, were randomly assigned to either an aerobic exercise training or control condition. Aerobic exercise training consisted of three 45-minute sessions of cycle ergometry exercise per week at 70-80% of age-predicted maximum heart rate for ten weeks. The aerobic exercise training resulted in a significant decrease in submaximal heart rate from 176 to 150 beats per minute to a fixed work rate of 150 watts (p < .01). This training effect was accompanied by increases in the resting level of the following lymphocyte subpopulations: CD2 (1717 vs 2183 mm3; p < .01), CD4 (942 vs 1280 mm3; p < .01), CD45RA+CD4+ (312 vs 595 mm3; p < .01), CD8 (655 vs 816 mm3; p < .05), and CD20 (162 vs 244 mm3; p < .01) cell counts. These findings indicate that several lymphocyte subpopulations are increased following a 10-week program of aerobic exercise training.