Shedding Light on Electrolytes


Many of us spend more time being active outdoors as the weather heats up, which means that we tend to sweat more during the hot months. When we sweat, we lose more than just water, we also lose electrolytes. The main ones we lose with sweat are sodium and chloride. To a lesser extent, we also lose magnesium, calcium and potassium.

So what exactly are electrolytes, and why are they important? Electrolytes are like the motor oil in your car—they don’t make the engine run, but they’re absolutely necessary to keep everything running smoothly. Proper functioning of the digestive, nervous, cardiac, and muscular systems depends on electrolyte levels. Muscle cramping, for example, is often a sign that you are dangerously low in electrolytes. It’s like the check oil light on a car’s dashboard; you never want to let it get that low.

Sodium is a primary regulator of our fluid balance. When sodium builds up and our kidneys can’t get rid of the excess, this can lead to high blood pressure. Conversely, if we don’t have enough salt in our diets (or we lose too much through sweat) water is drawn out of our cells, which may lead to low blood pressure and/or dehydration.

Having too little or too high levels of potassium can lead to muscle weakness, cramps, and abnormal heart rhythms. Most Americans over-consume sodium and under-consume potassium, so including lots of fresh fruits and vegetables is important to keep the balance between these electrolytes. Good sources of potassium are bananas, potatoes, tomatoes, lima beans, winter squash, avocado, and leafy green vegetables.

We don’t lose a lot of calcium through sweat, but it is still important to be aware of. While it’s probably most known for its role in bone building and preventing osteoporosis, calcium also has many other purposes. It helps the muscles contract (important for exercise), helps promote growth, helps blood clotting, and helps with hormones. Calcium also keeps our hearts beating, among other functions.

Magnesium makes the muscles relax (after calcium makes them contract), helps the body use energy, and is necessary for proper nerve and enzyme function. It’s involved in hundreds of reactions in our bodies and even helps regulate other minerals. It’s estimated that up to half of Americans are deficient in magnesium, and a true deficiency may cause symptoms such as nausea, vomiting, and weakness. Loss of appetite, muscle spasms, and seizures can also be symptoms. Get your magnesium through leafy greens, whole grains, seeds, nuts, and fortified cereals.

The key takeaway is that after high intensity exercise, exercising for more than an hour, or prolonged heat exposure, drinking only water is not effective for rehydration. For our body to actually retain the water and be able to use it, it must be consumed with electrolytes. To stay safe, replace fluids and electrolytes when you’re exercising even if you’re not thirsty. By the time you realize you’re thirsty, it’s often too late and dehydration has already struck. 

It’s recommended that if exercising for an hour, one should consume a minimum of 20 to 40 fluid ounces per hour. You should replace lost electrolytes at a rate of 200 to 500 mg per hour if hydrating at the recommended rate. There are endless options for electrolyte tablets, such as NUUN tabs or Ultima Replenisher powder. Replacing electrolytes doesn’t have to come solely from electrolyte tablets, either. You can also make an easy natural electrolyte drink by adding a pinch of high quality salt and a slice or two of lemon to a glass of water.