Sodium Needs of Athletes

Written by Keeley Drotz, RD, CD
Published in October 2006

(HealthCastle.com) Salt, or sodium, is a required nutrient in the diet. It helps regulate fluid balance and promotes proper muscle function. Unfortunately, most North Americans have developed an appetite for at least three times the sodium they need. The actual sodium need varies slightly from person to person, but a range of 1,800 to 2,400 milligrams, or one teaspoon of salt, is considered to be a healthy daily dose.

Like fluid requirements, daily sodium needs can also vary greatly among athletes. Some athletes have a greater sodium need because they lose more sodium in sweat. The sodium needs amount that is recommended during exercise is dependent on the amount of sweat produced.

For example, let say that you sweat about 1.5 liters per hour, and your sodium losses per liter may be about 750 milligrams. This means that in one hour, you lose 1125 milligrams of sodium. If you train for three hours, your total sodium sweat losses are 3,375 milligrams of sodium. Clearly, on days when you put in even more hours of training, you will increase your total sodium sweat losses further.

Having some salty foods and salting your food replaces some of the sodium lost in sweat. Besides having enough sodium in your diet, you can also consume a sports drink that contains adequate sodium. Check the sodium content of your favorite carbohydrate-electrolyte beverage. Pay attention to how many ounces you consume per hour and estimate your sodium intake per hour. You do not need to replace all of your sodium losses. You only need to consume enough sodium to prevent sodium levels from dropping too low. Sports drinks typically contain 20-60 milligrams of sodium per 100 milliliters.

Preventing Low Sodium in Athletes

During ultra endurance events such as adventure racing and Ironman triathlons, inadequate repletion of sodium can lead to a dangerous condition known as hyponatremia. For most athletes engaged in prolonged exercise, however, the danger of this condition is relatively low if they remain well fuelled and hydrated. Here are some tips on how you can prevent this condition from happening:

• Consume saltier foods such as pretzels, broth, sauces, salt bagels, V-8 juice leading up to race day or a long training session.
• Hydrate during exercise with a sports drink that contains sodium.
• If you are a salty sweater and you are involved in long distance events such as ultra marathons or triathlons, aim to consume 100-250 milligrams of sodium for every 8 ounces of water ingested during endurance training and racing.