8 Common Running Myths, Busted!

Myth: Muscle Cramps are Always Caused by Too Little Potassium

The Truth: Muscle spasms can certainly put a cramp in your running style, but that doesn’t mean you need to load up on potassium to prevent them. "Cramps are primarily caused by either being low on glucose (the form of sugar your muscles thrive on for energy) or low water and sodium levels," Olson says. When you are working out very hard (like lifting weights or with intense intervals), you use up glucose faster than what can be delivered to the muscles, and this causes that muscle-burning lactic acid to form. The best way to get rid of cramps caused by low glucose levels is to take a 60-90 second break to help rid your body of lactic acid and allow glucose to travel to the muscles, Olson says.

To prevent cramps caused by excessive sweating during steamy outdoor runs, be sure to stay well hydrated and nourished, Olson says. “When you sweat, sodium is also excreted, and water and sodium go hand-in-hand. Losing significant levels of potassium is actually quite hard to do. Potassium lives inside our cells and is not excreted as readily as sodium. Sodium, like water, resides outside the cells in your body.”