THE EFFECTS OF ALTERED EXERCISE DISTRIBUTION ON LYMPHOCYTE SUBPOPULATIONS

The effects of exercise distribution on lymphocyte count, lymphocyte s ubpopulations and plasma cortisol concentration in peripheral blood we re assessed in 19 healthy subjects. The subjects were randomly divided into group A (n = 10) or group B (n = 9) according to exercise distri bution. Both groups underwent a 10-week programme involving 5x2-week b locks: baseline (B), training period 1 (TP1), stabilisation 1 (S1), tr aining period 2 (TP2), and stabilisation 2 (S2). During B, S1 and S2 n ormal training was undertaken. During TP1 and TP2 the subjects increas ed the amount of training by 50% in week 1 and by 100% in week 2. Duri ng TP1 subjects in group A exercised 6 days . week(-1), while during T P2 these subjects exercised on 3 alternate days . week(-1), but double d the duration of each training session. The subjects in group B rever sed this training order. Blood was collected 36-42 h following exercis e period B, and at the end of periods TP1, S1, TP2 and 52, and also 12 -18 h following completion of exercise at the end of TP1 and TP2. Ther e were no significant differences (P > 0.05) between the 6 day . week( -1) programme and the 3 alternate day . week(-1) programme in total ly mphocyte count, CD3(+), CD4(+), CD8(+), CD16(+), or CD19(+) cells, the CD4:CD8 ratio, HLA-DR(+) (activated)T cells or plasma cortisol concen trations. Following both TP1 and TP2 there was a nonsignificant decrea se in lymphocyte subpopulations. However following both S1 and S2 (bas eline training) there was a significant increase in total lymphocyte c ount, CD3(+), CD4(+) and CD8(+) lymphocytes. The S2 variables statisti cally significant from B were: total lymphocyte count (P < 0.01), CD3( +) T-cells and percentage of circulating lymphocytes (P < 0.01), CD4() cells (P less than or equal to 0.0001), CD8(+) cells (P < 0.05), and HLA-DR(+) (activated) T-cells (P < 0.05). The results indicated that provided the amount of exercise is constant for a given period, then e xercise distribution is not a critical variable in the alteration of l ymphocyte subpopulations that may occur in response to overload traini ng. However 2 weeks of overload training followed by 2 weeks of active recovery (baseline) training may induce an increase in the lymphocyte count.