Effects of dehydration on neutrophil function after the match in female university soccer players

We investigated the effects of dehydration after a soccer match on immune function in 15 female university soccer players. Investigations were performed before and after a 90-minute soccer match. Body composition, serum myogenic enzymes, leukocyte counts and neutrophil functions (reactive oxygen species [ROS] production capability and phagocytic activity [PA]) were measured. All subjects showed significant body weight loss after the match due to loss of body water. Therefore, subjects were divided into two groups (the mild dehydration [MD] and severe dehydration [SD] groups) according to the changes in total protein concentration and the results were compared. Serum myogenic enzymes were found to increase significantly after the match in both groups, but the change ratios were not significantly different between groups. Leukocyte counts were found to increase significantly after the match in both groups, and the changes ratio in the SD group was significantly greater compared to the MD group. ROS production tended to increase in the MD group but decrease in the SD group, and PA significantly decreased in the SD group. These results suggested that immunosuppression is more likely to occur for those whose degree of dehydration is higher after physical exercise.