Send to

Choose Destination
Br J Sports Med. 2011 May;45(6):475-7. doi: 10.1136/bjsm.2010.075697. Epub 2010 Nov 22.

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?

Author information

Department of Human Biology, Sports Science Institute of South Africa, Newlands 7925, Cape Town, South Africa.


In 1991, we provided definitive evidence that exercise-associated hyponatraemia (EAH) is caused by abnormal fluid retention in those who overdrink during prolonged exercise, but this finding was ignored. Instead, in 1996, influential guidelines of the American College of Sports Medicine (ACSM) promoted the concept that athletes should drink 'as much as tolerable' during exercise. What followed was an epidemic of cases of EAH and its associated encephalopathy (EAHE). A recent study funded by the sports drink industry confirms our 1991 finding by showing that 95% of the variance in the serum sodium concentration during exercise can be explained by changes in body mass alone. The possibility is that commercial influence delayed the acceptance of our findings for two decades.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center