How Much Potassium Is Lost When You Work Out?

Sweat is made of water, sodium, chloride, potassium and a small amount of magnesium. The three minerals in sweat are known as electrolytes and are responsible for a variety of functions in the body including maintaining water balance, helping muscles contract and relax, and normal nerve functions. Small amounts of these electrolytes are lost through sweat, but most people can replace them through a normal diet that includes nutrient rich foods including fruits, vegetables, milk and milk products, meats and whole grains.

Potassium Level and Regulation

More sodium than potassium is lost through sweat. The amount of potassium lost through sweat is small and varies in each individual based on his level of potassium prior to exercising and his level of kidney function. In a healthy individual, the level of potassium does not change drastically -- normal blood level is 3.5 to 5 milliequivalents per liter -- as the body self-regulates by excreting less through urine and bowel movements. Potassium is absorbed from the small intestine, and approximately 80 to 90 percent is passed through the kidneys and eliminated via urination. The kidneys are responsible for filtering, reabsorbing and excreting potassium.

Potassium and Health

According to the 2010 Dietary Guidelines for Americans, 56 percent of Americans do not reach the adequate intake level of potassium -- 4,700 mg per day. This can lead to high blood pressure, increased risk of kidney stones and possibly osteoporosis. Increased intake of potassium may help prevent stroke and coronary heart disease. Overall, Americans consume an excessive amount of sodium and not enough potassium.

Exercise and Potassium

Stay adequately hydrated before, during and after exercise for optimal performance and prevention of the consequences of dehydration. Drink beverages containing carbohydrates -- sugar, for example -- and electrolytes -- sodium, potassium -- for intense exercise sessions lasting longer than one hour. After exercise, replace fluid with at least 16 to 24 ounces, or 2 to 3 cups, of fluid per pound of body weight lost during exercise.

Potassium in Foods

Consume foods that contain water and electrolytes after exercise so the body will recover at an adequate rate. Foods that contain the most potassium include avocados, bananas, cantaloupe, dried fruits, artichokes, bamboo shoots, beet greens and dried beans.