Nauseous After A Workout? The Science Behind Why & What To Do

Picture this: You come in from a long run on a hot day or walk out of a hot yoga class dripping with sweat, and instead of feeling energized and on an endorphin high, you're slightly…queasy? 

Nausea after is a relatively common (if unpleasant) side effect of getting your sweat on. And when it follows a particularly long and intense workout in a hot environment, electrolytes, or lack thereof, may be to blame. 

During exercise, muscle exertion creates heat. Sensing this, the body transfers heat to water, which is released as sweat that evaporates off of the body. But besides heat, sweat releases electrolytes2 like sodium, potassium, and chloride. If these all-important minerals aren't adequately replenished, imbalances like hyponatremia, or low blood sodium levels, can occur. 

The most commonly depleted electrolyte, according to registered dietitian and sports nutritionist Marie Spano, M.S., R.D., is sodium. "It is not common to have low levels of other electrolytes in the blood," Spano says. Too low sodium levels (or any electrolyte levels, for that matter) are more likely with intense exercise in hot and humid environments2. 

While drinking enough water is key to overall health, overdoing it can further exacerbate a sodium imbalance. During extended periods of exercise, drinking too much of any low-sodium beverage can dilute your body's electrolyte stores and increase your risk of hyponatremia, Spano says. 

Besides nausea, hyponatremia can cause headaches3, weakness, fatigue, confusion, muscle aches, twitching, cramps, vomiting, and even delirium. 

That said, Spano points out that the average person probably doesn't need to worry about hyponatremia unless they're working out for an extended period or outside. If you're hitting an air-conditioned gym for 30 minutes or less, you probably don't need to be pounding sports drinks. But longer bouts of exercise in hot climates put you at risk.

To replenish electrolytes, many people opt for a premade electrolyte drink (find some of the healthiest options here). But simply adding a pinch of salt to your water will do the trick. Coconut water is often touted as "nature's electrolyte drink" thanks to its potassium and magnesium content, but it lacks sodium, so you may want to add a pinch of salt if you go that route. Or, spice things up with our assistant health and beauty editor's favorite, nature's gatorade, which boasts more electrolytes than its namesake.

 You can also replenish electrolytes with a thoughtful post-workout snack. 

While Spano says that potassium, magnesium, and calcium imbalances are usually reserved for clinical conditions where people are hospitalized, most people don't consume enough of the important nutrients. Replenish potassium with bananas, spinach, potatoes, and citrus fruits. Opt for nuts, seeds, and beans to get your magnesium fill and dairy products for a calcium hit.