Immune Function in Athletes Versus Nonathletes

The purpose of this study was to compare natural killer cell cytotoxic activity (NKCA) and Con A-induced lymphocyte proliferation (T cell function) in athletes versus nonathletes, with measurement of natural killer (NK) and T cells to allow a comparison on a "per-cell" adjusted basis. Eighteen young male endurance athletes (10 runners and 8 cyclists) with a mean VO₂max of 70.7 ± 1.3 ml · kg^-1 · min^-1 and 6.6 ± 0.8 years of competitive experience were compared with 11 nonathletic male adults (47.6 ± 3.1 ml · kg^-1 · min^-1). Concentrations of circulating leukocyte and lymphocyte subsets, including NK and T cells, were not significantly different between groups. NKCA and T cell function also did not differ between groups, whether expressed unadjusted or adjusted on a per-cell basis. For all subjects combined, both NKCA and T cell function were unrelated to VO₂max (r = 0.005, p = 0.98; r = 0.007, p = 0.97, respectively). These data do not support the contention that immune function, as measured in this study, is altered in endurance athletes.

Key words

Exercise training - lymphocytes - natural killer cells - T cells - immunity