Novice athletes who are training for marathon running events may be a danger from exercise-associated hyponatremia (EAH) that can develop from low levels of sodium in the body. The risk to the condition is heightened when the athletes drink excess amounts of fluids during exercises.
Awareness of EAH is increasing, but athletes, coaches, and medical professionals need reliable information on the causes, recognition, prevention, and treatment of this potentially fatal condition.
To address this need, the July/August Clinical Journal of Sport Medicine presents a position statement on current understanding of EAH in endurance athletes. The statement summarizes the conclusions of a panel of medical and scientific experts who met at the 1st International Exercise-Associated Hyponatremia Consensus Development Conference, held in Cape Town, South Africa, in March 2005.
The report summarizes known risk factors for EAH, including low body weight and female sex. Novice athletes and those running at a slow pace—especially with race times over four hours—are also at high risk.
However, the main factor leading to EAH is drinking too much fluid during exercise.
Hyponatremia may occur whether the athlete drinks water or sodium-containing sport drinks. Excessive fluid dilutes the body's sodium level, interfering with the body's normal regulatory processes.
The key to preventing EAH is to avoid drinking a larger volume of fluid than the body loses in the form of sweat and urine. Formulas are available for estimating hourly sweat loss during exercise—however; a good rule of thumb is to drink only when thirsty.
Increasing sodium intake through sport drinks or salt tablets does not appear to reduce the risk of EAH in those who over drink during exercise.
Planners of marathons and other endurance events can discourage over-consumption of fluid by making sure water stations aren't placed too close together. Information on pre-race weights should be available to medical personnel evaluating collapsed athletes—an increase in body weight is an important clue to EAH. The report includes up-to-date recommendations for doctors and other health professionals involved in evaluating and treating athletes with possible EAH.
Recent years have seen growing concern about the risk of EAH in endurance athletes, particularly with the increased popularity of marathon running for previously sedentary people. The panel members hope their consensus statement will "curtail the growing problem of EAH by disseminating the most current information on the prevalence, nature and treatment of this disorder." The report provides a "snapshot in time" of the current state of knowledge regarding EAH—the position statement will be revised as new information is discovered. Suggested research priorities include the establishment of an international registry to include all new cases of EAH.
Medindia on Exercise-Associated-Hyponatremia- Further information
Hyponatremia: This is a condition in which the body's sodium content reduces by the intake of excess amount of water. Hyponatremia can cause lethargy, confusion, agitation, seizures and may at times lead to death. Some symptoms of the condition are muscle cramps, nausea and disorientation.
Exercise-Associated-Hyponatremia: This condition is so called as often this is related to people who exercise a lot and keep on having water to keep them hydrated. At times the feelings of this condition are similar to dehydration and athletes may increase their water intake, only to increase their risk to hyponatremia more.