THE IMPACT OF SOCCER TRAINING ON THE IMMUNE-SYSTEM

Objective. The aim of this study was to evaluate whether the level of some immune markers changed in soccer players during pre-season and du ring playing-season. Design.,Sn observational study for one soccer sea son (one gear), Setting, Professional soccer players. Participants. Th irteen professional soccer players (age: 26.3+/-3.7 Sears). Measures. The effect of 11 months of soccer training sessions and matches on cir culating leukocyte and lymphocyte subpopulations was investigated. Blo od samples were taken before the season and also 6 weeks, 6 months and 11 months later. All samples were taken at 08:00h. Results, Total lym phocyte counts did not change in all samples. During the pre-season, h owever, the concentrations of some inflammatory lymphocyte subpopulati ons were changed: CD4CD45RA+ was elevated and CD57 and CD8CD57 showed a significant decrease (p<0.05), At the end of the competitive period, CD4 and CD8 were increased. At the end of the season there were signi ficant changes in some immune cells: total leukocyte and neutrophil nu mber and CD8+ cell concentration was increased compared to pre-season values and the CD4/CD8 ratio was decreased. Conclusions. The results s uggest that athletes exposed to a longterm training periods can exhibi t variations in some immune cells. The clinical significance of these variations requires more detailed investigation.