The American College of Sports Medicine (ACSM) has released evidence-based recommendations for athletes to prevent hyponatremia and dehydration during sporting events. The report, which is based on the analysis of several previous studies, was published in the June 2005 issue of Current Sports Medicine Reports.

The study reinforces the importance of managing hyponatremia and dehydration in persons who participate in endurance events such as races and marathons. The ACSM recommends the following procedures to help prevent these conditions:

• Work to minimize the risk of hyponatremia and dehydration. Hyponatremia occurs when the athlete drinks too much liquid, causing the body’s sodium levels to dilute. The condition is rare and usually affects athletes participating in running events lasting longer than four hours. Dehydration occurs much more frequently, and the ACSM recommends avoiding over- or under-drinking when running.

• Drink on a schedule to match fluid loss. Athletes should know their body’s average hourly sweat rate and drink the appropriate amount of fluids to replace what was lost each hour. The study also recommends drinking early and at regular intervals during a race rather than all at once. Drinking constantly over a set period of time rehydrates more effectively than rapid fluid replacement.

• Consume salty foods and beverages. Eating foods with high levels of sodium helps stimulate fluid intake and promote fluid retention. The ACSM recommends that endurance athletes ingest salty snacks and fluids to help offset the loss of salt in sweat and prevent hyponatremia.