Breakthrough in Hydration and Athletic Performance
Study confirms that relying on thirst is an effective strategy for runners
Sherbrooke, le 4 novembre 2013 – Does planning fluid intake and drinking even when you're not thirsty maximize athletic performance? Contrary to this popular belief, relying solely on thirst to guide fluid intake has no negative impact on performance. That is the gist of an article appearing in the European Journal of Applied Physiology and highlighting the work of Tommy Dion, a master's student in physical activity at the Université de Sherbrooke under the direction of Professor Éric Goulet.
When the Student Surpasses the Master
This study was conducted within the context of a previous meta-analysis carried out by Professor Goulet that revealed that endurance athletes didn't need to program their fluid intake during exercise to achieve optimal performance. Professor Goulet indicated that no research had been conducted on assessing fluid intake based on thirst sensation among runners. Given the popularity of running, carrying out such a study made good sense. This is the point at which Tommy Dion's master's project came into the picture. Its purpose is to assess the impact of fluid intake dictated by thirst sensation during a half-marathon under controlled laboratory conditions.
As Tommy Dion pointed out, "not only is the study novel because it revolutionizes an approach that has stood for years, but it's also the very first of its kind conducted exclusively during running exercise."
Thirst-Dictated Intake Is both Effective and Much Less Complicated
Tommy Dion therefore asked 10 trained runners to do several half-marathons at 30°C. The hydrated group had to drink so as to limit bodyweight loss to 1%, whereas the thirst-driven group only drank when they felt thirsty. Although the hydrated group had fluid intakes nearly four times that of the thirst-driven group, participants who drank according to thirst evidenced no reduction in performance despite losing more than 3% of their body weight through dehydration.
The study therefore made it possible to demonstrate that, during running exercise lasting less than two hours, adopting a thirst-driven intake strategy is just as effective and much less complicated than a programmed hydration strategy.
It should also be noted that a 3% loss of body weight due to dehydration is not harmful to health. Dion pointed out, however, that "athletes that finish their races with significantly high levels of dehydration and facing another race the following day need to adopt a more aggressive rehydration strategy."
A Reference in the Field of Hydration
A number of universities have taken an interest in the relationship between performance and various other fields such as nutrition, physiology, and training methods. Only a few are investigating the link with hydration. As Tommy Dion confirmed, "as the result of Professor Goulet's recent work, the team of researchers at the Faculty of Physical Education and Sports definitely ranks among the field's benchmark groups."
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Mélissa Casavant, Communications Officer
Faculty of Physical Education and Sports | Université de Sherbrooke
819 821-8000, extension 65411 |Melissa.Casavant@USherbrooke.ca