According to internationally recognized human performance expert Tim Noakes, overhydration poses a much more common and dangerous risk to endurance athletes than dehydration. The stance Dr. Noakes takes against the overuse of sports drinks during prolonged exercise, featured in his acclaimed new book Waterlogged: The Serious Problem of Overhydration in Endurance Sports, runs counter to decades of widely accepted marketing messages from the sports drink industry about hydration. But Noakes' claims are now being confirmed by one of the world's most prominent medical journals.
The July 2012 issue of the British Medical Journal (volume 345, issue 7866) features an exposé titled “The Truth About Sports Drinks,” offering seven articles highly critical of sports and energy drinks, the manufacturers of those drinks, and the scientists who have been sponsored by those companies. The researchers find that evidence is sorely lacking to support claims made over the past 40 years that sports drinks are needed to “stay ahead of thirst” and prevent dehydration.
Just as he points out in Waterlogged, Noakes says these flawed beliefs come from the sports drink industry itself, which has instilled in people the belief that fluid intake plays just as big a role in athletic performance as proper training. “It became common for athletes to state that the reason why they ran poorly during a race was not because they had trained either too little or too much, but because they had dehydrated,” Noakes is quoted as saying in an article by the journal's investigations editor, Deborah Cohen.
Noakes also criticizes the relevance to the general population of studies conducted by the sports drink industry, since those studies are done on highly trained volunteers who exercise at high intensity for long periods. “They are never going to study a person who trains for two hours per week, who walks most the marathon—which form the majority of users of sports drinks,” he is quoted as saying in Cohen's article. These people, however, are targeted by the manufacturers of sports drinks in their marketing programs.
Similar to his book, a commentary by Noakes in the journal, addressing the role of hydration in health and exercise, stresses again that dehydration is not a medical illness, and its only symptom is thirst. He offers that there is nearly no risk of dehydration occurring in healthy athletes with access to ample fluid while competing in a modern endurance event. “Over the past 40 years humans have been misled—mainly by the marketing departments of companies selling sports drinks—to believe that they need to drink to be optimally hydrated,” Noakes writes.
Other articles in the journal lend further credence to the claims Noakes makes in Waterlogged, including an in-depth look at sports drink advertising, which found 84% of 431 performance-enhancing claims being judged to be at a high risk of bias; the validity of the European Food Safety Authority's (EFSA) assessment of sports drinks, in which the authors are highly critical of the two claims approved by the EFSA in regards to sports drinks not only improving water absorption during exercise, but also maintaining endurance performance; a “mythbusting” article that shows that there is no reason for people to drink before they feel thirsty; and recommendations for staying hydrated, which conclude that intake of liquid at rates higher than sport body recommendations confers no advantages for athletes.
In Waterlogged, which has been featured in publications such as Runner's World, Running Times, Outside, Shape, Triathlete, and UltraRunner, Noakes outlines practices that endurance athletes should follow, variables they should consider, and guidelines they should use in maintaining proper fluid balance in sport training and performance. A veteran of more than 70 marathons and ultramarathons, Noakes offers prescriptive advice to fellow endurance athletes as the culmination of decades of research dedicated to the issue of overhydration.