Abstract des Autors

To examine controversies about hydration strategies, participants (383 starters) of a 161 km ultramarathon (maximum temperature 39.0°C) underwent body weight measurements before, during and after the race; and completed a post-race questionnaire on drinking strategies and sodium supplementation use during 4 race segments. Drinking to thirst was the most common (p < 0.01) drinking strategy (used by 67.0 percent during at least one segment) and most runners (95.6 percent) used sodium supplementation during at least one segment. There was no difference in the extent of weight loss (mean 2.0-3.1 percent) or the weight change pattern when comparing groups using different hydration strategies. Among top-10 finishers, half had lost more than 2 percent of starting body weight by 90 km. We conclude that weight loss greater than 2 percent does not necessarily have adverse consequences on performance, and use of sodium supplements or drinking beyond thirst is not required to maintain hydration during ultra-endurance events with high thermal stress. Verf.-Referat