T-lymphocyte populations following a period of high volume training in female soccer players.

Abstract Purpose To investigate the T-lymphocyte response to a period of increased training volume in trained females compared to habitual activity in female controls. Methods Thirteen trained female (19.8 ± 1.9 yrs) soccer players were monitored during a two-week long high volume training period (increased by 39%) and thirteen female untrained (20.5 ± 2.2 yrs) controls were monitored during two-weeks of habitual activity. Blood lymphocytes, collected at rest, were isolated before and after the two-week period. Isolated lymphocytes were assessed for the cell surface expression of the co-receptor CD28, a marker of T-lymphocyte naivety, and CD57 a marker used to identify highly-differentiated T-lymphocytes. Co-expression of these markers was identified on helper CD4 + and cytotoxic CD8 + T-lymphocytes. In addition a further population of γδ + T-lymphocytes were identified. Plasma was used to determine Cytomegalovirus (CMV) serostatus. Results No difference was observed in the T-lymphocyte populations following the two-week period of increased volume training. At baseline the number of total CD3 + , cytotoxic CD8 + , naive (CD8 + CD28 + CD57 − ), intermediate (CD8 + CD28 + CD57 + ) T-lymphocytes and the number and proportion of γδ + T-lymphocytes were greater in the trained compared to the untrained females ( p +  T-lymphocytes was greater in the untrained compared to the trained ( p + :CD8 + ratio was also greater in the untrained females ( p + T-lymphocyte population. 8% of the untrained group was defined as positive for CMV whereas 23% of the trained group was positive for CMV. However, CMV was not a significant covariate in the analysis of T-lymphocyte proportions. Conclusion The period of high volume training had no effect on T-lymphocyte populations in trained females. However, baseline training status differences were evident between groups. This indicates that long-term exercise training, as opposed to short-term changes in exercise volume, appears to elicit discernible changes in the composition of the blood T-lymphocyte pool.