Prevention

EAH is caused primarily by the consumption of fluid in excess of urinary and sweat losses

• therefore, it follows that any individual participating in endurance exercise, and particularly those at increased risk for EAH, should avoid over consumption of fluids before, during and after exercise
• blanket universal guidelines are neither possible nor appropriate because there is a wide variability in sweat rates and renal water excretory capacity during exercise, both among individuals and in the same individual depending on ambient environmental conditions during the time of exercise

Basic advice:

• Ad libitum fluid intake- drink to perceived need drink only according to thirst
• avoid excessive fluid before during and after endurance event
• drink to thirst
• monitor body weight (Weigh athletes before start?)
• aim not to gain weight during endurance exercise and expect small weight loss 1-2%
• no evidence that sodium supplementation and the use of sport drinks can limit the development of EAH (drinks < 135mmol Na+, excretion of sodium through urine)

www.overhydration.org

Reference:

• Hew-Butler T, Ayus JC, Kipps C, Maughan RJ, Mettler S, Meeuwisse WH, Page AJ, Reid SA, Rehrer NJ, Roberts WO, Rogers IR, Rosner MH, Siegel AJ, Speedy DB, Stuempfle KJ, Verbalis JG, Weschler LB, Wharam P.Statement of the Second International Exercise-Associated Hyponatremia Consensus Development Conference, New Zealand, 2007. Clin J Sport Med. 2008 Mar;18(2):111-21