The objective of our study was to analyse the total body water (TBW), intracellular water (ICW) and extracellular water (ECW) dynamics for two groups of athletes (elite and hobby) during one race (the Half Ironman). Forty-two male triathletes volunteered to participate in the study.
Their body composition parameters were determined with the Tanita MC-980 multi-frequency segmental body composition analyser. The results are presented as means and standard deviations.
The pre- and post-race results for both groups were analysed with paired t-tests. The pre-race results for both groups were compared using non-paired t-tests.
The associations between body composition variables and race times were investigated with Pearson's correlation analyses. The statistical significance was set at P LESS-THAN OR EQUAL TO 0.05.
Professional athletes achieved higher hydration rates before performance in terms of both the TBW percentage (P = 0.005) and the ICW percentage (P = 0.006) parameters. However, there were no significant differences between the groups of athletes in water-control ability during endurance exercise.
In both groups of athletes, significant changes in water balance and total weight loss were observed during the race.