Effects of long-term running on lymphocyte subpopulations

Thirteen healthy members (11 males and 2 females; mean age 19.8 years) of an athletic club underwent a long-term exercise program (five 8-km runnings per week for 40 weeks) as regular training for their club. The circulating lymphocyte number, T lymphocyte percentage, and OKT4/OKT8 ratio did not change through the 40-week training period. However, suppressor/inducer (Leu3a+Leu8+) and suppressor T cells (Leu2a+Leu15+) significantly increased. In contrast, helper (Leu3a+Leu8-) and cytotoxic T cells (Leu2a+Leu15-) significantly decreased. On the other hand, there was no change in three males (mean age 18.7 years) without the long-term exercise program. These results suggest that long-term running may induce some change in lymphocyte subpopulations.