Sports drinks not worth their salt during exercise
3 December 2010
Claims that sodium (salt)-containing sports drinks can prevent exercise-associated hyponatraemia (low salt levels in the blood - EAH) are false and may have led to numerous cases of illness and deaths, an expert claims (2010 Nov 22, online).
Writing in the British Journal of Sports Medicine, Professor Timothy Noakes of the Sports Science Institute of South Africa said evidence has been building since the early 1990s of the links between consuming sports drinks and EAH. However, he believes a well-orchestrated, commercially driven campaign has succeeded in overwhelming these findings.
Since the 1996 guideline from the American College of Sports Medicine recommended athletes drink "as much as tolerable" during exercise, Professor Noakes says there have been at least 12 documented deaths and 1641 serious cases of EAH or associated encephalopathy (brain disease). "Overconsumption of sports drinks, like the overconsumption of water, can cause EAH and EAHE", he said.
"Two studies, funded by a company which has consistently promoted the (false) concept that sodium ingestion during exercise can prevent EAH, now prove the opposite", he said.
Sports Dietitians Australia advises that: "Sports drinks assist ... by replacing fluids lost in sweat and also assist with refuelling targets to replenish glycogen (energy) stores. When aggressive re-hydration strategies are required, drinks with a higher sodium content may be more useful."
Neither Sports Dietitians Australia nor Sports Medicine Australia had responded at the time of publication.
Last Reviewed: 03 December 2010
- 1. Noakes TD. Changes in body mass alone explain almost all of the variance in the serum sodium concentrations during prolonged exercise. Has commercial influence impeded scientific endeavour? Br J Sports Med 2010 Nov 22. [Epub ahead of print]. http://bjsm.bmj.com/content/early/2010/10/18/bjsm.2010.075697.extract (accessed Dec 2010).
2. Convertino VA, Armstrong LE, Coyle EF, et al. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc 1996;28: i-vii. http://journals.lww.com/acsm-msse/Fulltext/2007/02000/Exercise_and_Fluid_Replacement.22.aspx (accessed Dec 2010).
3. Sports Dietitians Australia. Fluids in sports. http://www.sportsdietitians.com.au/content/510/FluidsinSport (accessed Dec 2010).
