The Ironman Triathlon is a long-lasting competition where commonly electrolyte changes are observed. Dehydration and hyponatremia are prevalent and the differential diagnosis between them should take into account the body weight variation of the athlete. Nevertheless, one should also consider that variations are a summation of water and no-water sources, being necessary to apply a correction factor to evaluate the real water condition of the athlete. Objective: To evaluate the water condition of the athlete based on body weight changes with and without correction factor applied.
Twenty-six athletes were weighed in three different times (two days before the competition, immediately before and after performance). The water was classified by calculating the percentage of isolated body weight variation and application of correction factor of 1kg proportional to the athlete of 70kg. In addition, the main clinical signs and symptoms were recorded.
In the 48 hours before the start there was an average weight gain of 1.2kg. After the race, 23 (88.4%) athletes were classified as dehydrated initially but after applying the correction factor to the weight change, this number dropped to 12 (46.1%). Those classified as severe dehydration decreased by 7 (26.2%) to no athlete. Ten athletes (3.8%) presented signs and symptoms of dehydration.
The classification of hydration status based on water loss during the race was significantly modified by the application of the correction factor, and its use is justified by evidence that weight gain within 48 hours prior to the race is possibly related to the muscle glycogen and water accumulation (no intravascular water sources).
dehydration; body composition; athletes