Written by: Christina Schoerner, MS RD
I can remember the days when I played tennis for hours in the hot Georgia sun preparing for my high school regional and state tennis tournaments. Pushing my body in the intense heat led to dehydration and cramping. My coach would toss a banana across the fence. “Eat it, it has potassium,” she called. So exactly why did she toss me a banana? What role does potassium play in exercise?
In the body, potassium is the major intracellular cation. It works along with sodium to maintain the body’s water balance. Having potassium levels that are below the recommended level may be a contributing factor to muscle cramps 1. Consuming foods rich in potassium can replace what is lost from muscle during exercise and the smaller amounts lost in sweat 2.
On those hot spring days, I was most likely experiencing heat cramps. Heat cramps are muscle spasms that occur during or after vigorous activity in a hot environment. Hydration, sodium, potassium, magnesium and calcium all play a contributing role in heat cramps. The body can lose as much as 6 g per day engaging in activity that causes profuse sweating 1.
Recommendations from the National Research Council suggest intake of 4,700 mg of potassium a day for adults. However, most Americans do not meet this recommended intake because of the lack of fruits and vegetables consumed in their diet.
Was my tennis coach right when she tossed me a banana in order to increase my potassium intake? YES. Bananas are an excellent source of potassium along with other fruits and vegetables. Foods that contain greater than 300 mg of potassium per serving are considered exceptionally rich. See the list below to see what potassium rich sources to include in your diet.
Potassium also plays an important role in health, particularly blood pressure health. It is known that a diet low in potassium and high in sodium is a leading link to high blood pressure. So consuming a diet rich in potassium will not only replenish your body during and after exercise, but it can benefit those who have hypertension 2.
|Potassium Rich FoodsMore than 300 mg per serving|
|Winter squash||Banana, Oranges|
|Avocado||Prune and Carrot Juice|
|Brussels Sprouts||Cantaloupe, Honeydew Melon|
|Potatoes, Yams||Papaya, Peaches|
|Green Leafy Vegetables||Raisins|
|Zucchini, Broccoli||Yogurt, Milk|
|Mango, Apricots||Halibut, Tuna, Cod, Trout|
- Gaby, Alan. Nutritional Interventions for Muscle Cramps. Integrative Medicine. 2008. 6:20-23.
- Anderson, J., Young, L., Long, E. Potassium and Health. Colorado State University. http://www.ext.colostate.edu/pubs/foodnut/09355.html
- Gropper, S., Smith, J., Groff, J. Advanced Nutrition and Human Metabolism. 5 ed. Wadsworth, Cengage Learning. 2009.