Effects of resistance training on resting immune parameters in women.

The aim of this investigation was to determine whether intense resistance training of 6 months duration influenced resting immune parameters. Previously untrained women underwent one of four training programs or were non-training controls (CON, n=7). The resistance-training groups trained for total body power (TP, n=16), total body hypertrophy (TH, n=18), upper body power (UP, n=15) or upper body hypertrophy (UH, n=15). Immune parameters were measured from a fasting morning blood draw in September/October (0 months, t(0)), November/December (3 months, t(3)), and April/May (6 months, t(6)). Lymphocyte subsets [CD4+ T cells, CD8+ T cells, natural killer cells (NK), and B cells], and mitogen-stimulated proliferation were measured. The concentration of NK cells increased ( P<0.001) after 3 months of training for the resistance-training groups but not the CON group. This increase was not present after 6 months of training, thus it was a transient change. Lymphocyte proliferation responses were similar across time for the resistance-trained and CON groups for all stimulation conditions. Thus, resistance training induces a transient increase in NK cells but has little effect on lymphocyte trafficking or proliferation. This was consistent despite differences in the volume of muscle mass trained or the manner of training (power verses hypertrophy).