Hydration Updated

Hydration update

As every sweat soaked runner collapsing home from the midday heat knows, fluid is essential for enjoying and optimising exercise performance.  However a BBC and British Medical Journal expose of sports drinks companies and sports nutrition research released last year has put traditional hydration guidelines under the spotlight. 

Professor Tim Noakes, an extremely well respected figure in sports science, had become sceptical of current hydration guidelines when investigating exercise-associated hyponatremia (EAH). He concluded that sports drink marketing messages inadvertently caused athletes to over-drink, with the most serious consequences being death. While much of what the BMJ argued has been hotly debated, Noakes’ claims has shaken up the sports nutrition world, and certainly influenced the way Trailblazer Nutrition create hydration guidelines.

Professor Noakes alleged that the American College of Sports Medicine’s (ACSM) 1996 position stand on hydration during exercise was inaccurate and encouraged consumption of sports drinks in dangerous amounts. He was specifically referring to the ACSM statement “During exercise, athletes should start drinking early and at regular intervals in an attempt to consume fluids at a rate sufficient to replace all the water lost through sweating (i.e., body weight loss), or consume the maximal amount that can be tolerated.”1

Professor Noakes argued that this encouraged people exercising to ignore their thirst mechanism, drink in dangerous quantities, thus increasing the chance of EAH. Noakes argues that dehydration’s only symptom is thirst, the effect of which is to induce drinking, and therefore athletes can optimise their hydration status by drinking according to the their thirst2.

He states: “There is barely any risk that dehydration can occur in healthy athletes competing in a modern endurance event in which ample fluid is available.2

The ACSM does update its position stands regularly and the most recent stand was released in 2007. Its key statement was Individuals should develop customized fluid replacement programs that prevent excessive (2% body weight reductions from baseline body weight) dehydration.3

Two camps have formed, drink to thirst vs drink to a plan.

So what is the best approach?

One of the key statements I noted from Prof Noakes was “As the sensation of thirst rises, exercise performance becomes progressively impaired.2Meaning as we get dehydrated our performance will deteriorate as the body aims to preserve body water (by sweating less), and also try to seek out water. However, to optimise performance through nutrition, which is what we do at Trailblazer, a modified approach is needed. Trailblazer takes on board Noakes’ advice regarding the prevention of EAH, but examines individual factors to design personalised plans to optimise hydration and performance – we take the best of both approaches.

Considerations for the Motatapu

First of all, an individualised approach that you have practised in advance is essential. Prior to this years London marathon Great British Olympic marathoner Liz Yelling’s most important piece of race advice was “When you stand on that start line you must know your nutrition and hydration strategy…. It’s very personal so you must have practised it in training.”

At Trailblazer we look at each individual and devise a conservative hydration plan in advance of the event which utilizes personal fluid carried by the athlete that will prevent dehydration and optimise performance. Athletes can then ‘drink to thirst’ at aid stations (and streams) if necessary.

This strategy optimises performance by ensuring you carry everything you need and nothing you don’t. Importantly, it allows us to control carbohydrate intake which is key for performance. There is an optimal range of carbohydrate intake, too much and risk gastro problems, too little and you will not reach your potential.

Drinking carbohydrate containing drinks to thirst results in an unknown carbohydrate intake. By planning your fluid intake (and therefore corresponding carbohydrate intake from fluid) you can then work out the perfect amount of gels etc required to supplement the carbohydrate content of your drink. By drinking plain water to thirst at aid stations, you can drink as much or as little as you like without affecting your carbohydrate intake.

At Trailblazer Nutrition we have mixed the scientific literature with practical considerations and the needs of out athletes so we can optimise your performance so you can achieve your goals and enjoy your chosen event.

Happy Trailblazing!

  1. 1.Convertino VA, Armstrong LE, Coyle EF, Mack GW, Sawka MN, Senay LC Jr, Sherman WM. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 1996 Jan;28(1):i-vii.
  2. 2. Noakes T. Commentary. BMJ 2012; 345, July 2012.
  3. 3. Exercise and Fluid Replacement. Position Stand. Medicine and science in sports. 2007