Sweat is made up of water and electrolytes, primarily sodium and potassium. (That’s why our sweat has a salty taste to it). Sweat also contains traces of calcium, magnesium, and chlorine.

If you’re sweating a lot, it’s important to replace what you’ve lost to keep your body chemistry in balance, says Felicia D. Stoler, R.D.N., an exercise physiologist and sports nutritionist.

If you’re just doing moderate exercise for an hour or less, plain water will suffice, but if it’s more than an hour or in extreme conditions (an intense workout, hot yoga, high humidity, high altitude, etc.), add electrolytes to the mix.

Why?

Put simply, electrolytes are salts that conduct electricity in water by separating into positive and negative charges. Each electrolyte serves a different function in the body, keeping processes like nerve conduction, muscle contraction, and fluid balance running smoothly.

All of them are important, but in reality, most athletes only need to worry about sodium while working out, because it’s the main electrolyte we lose through sweat.

When you think electrolytes, you probably think of those sugary sports drinks (which can be helpful, and we’ll discuss them soon), but there are also many other foods that can replenish your supply.

Here, we run down the five best sources for electrolytes that you should fill up on after your next brutal workout or perhaps at the end of a grueling hike, and why they’re so good for you.

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