Does Running Deplete Your Potassium?

Sweating when running can lead to potassium losses.
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Electrolytes are electrically charged particles in your body that conduct electrical impulses to keep your nerves transmitting, muscles contracting and heart beating. Common electrolytes in your body include potassium, sodium, chloride, magnesium and calcium. If you are an avid runner who sweats through an extended running session, you will lose some potassium via your sweat. While this is not always cause for concern, competitive and distance runners must replace potassium to prevent adverse side effects.

Potassium Lost

Sodium and potassium are the electrolytes lost in greatest amounts when you sweat, according to “Running Times” magazine. You can lose anywhere from 0.5 to 5 pounds of sweat per hour. Each pound of sweat lost represents about 80 to 100 milligrams of potassium lost. If you lose as little as 2 percent of your body’s typical water weight, you can experience changes in performance and cardiac function, according to marathon coaching group Team Oregon.


Potassium depletion when running can be difficult to diagnose. You may mistake the normal aches and pains of running long distances, such as muscle aches or nausea, for more serious side effects. Common signs you may have lost excess potassium include muscle or stomach cramping, feeling lightheaded, mental confusion and muscle spasms.

Electrolyte Replacement

Potassium is an abundant electrolyte in fruits and vegetables. Your diet likely has enough potassium in it without your needing to take in extra potassium before a running session. How long you run, how hard you run and how hot it is and how hard you run can all affect your need for electrolyte replacement. The best time to replace potassium is as you are running.

During Your Run

Patti and Warren Finke, sports and conditioning coaches with Team Oregon, recommend consuming 6 to 8 ounces of fluids every 15 to 20 minutes while you are running. If you experience electrolyte loss symptoms, you might choose to drink a sports drink during exercise.

After Your Run

After you finish your running session, consume a banana or citrus fruits. Both of these are high in potassium and can help to replace potassium losses from running before you experience adverse side effects. A small banana also packs a significant amount of potassium -- about 450 milligrams compared with a sports drink’s average 30 milligrams, according to “Running Times.” Another good post-running meal is 8 ounces of yogurt and a can of chicken noodle soup. This replaces both potassium and sodium lost via your sweat.

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