- Electrolytes like sodium are key for a healthy body and brain, and too little of them can be risky.
- A lack of electrolytes can cause a range of health issues from mild headache to life-threatening brain damage.
- To prevent health risks, avoid drinking too much water and consider supplementing with sports drinks.
Record-breaking heat waves across the US and worldwide this year have made it more important than ever to stay hydrated, especially if you’re exercising.
But it’s possible to drink too much water, throwing off your body’s delicate balance and leading to major side effects from nausea to disorientation, according to an exercise scientist.
Hydrating isn’t the only necessity during hot weather or sweaty activity, since you also need to worry about keeping the right mix of electrolytes, or minerals that are crucial for managing fluid levels and regulating muscle and nerve health.
Too little electrolytes is rare but serious and sometimes life-threatening condition called hyponatremia, said Sean Langan, an associate research director at the University of Connecticut’s Korey Stringer Institute
“Hyponatremia is a fancy term for low sodium. It’s relatively rare, but it can lead to sudden death in athletes,” he told Insider.
The most common scenario for electrolyte issues in otherwise healthy people is when athletes are exercising for a long period of time at a low intensity and drinking plenty of water, but not sweating it out fast enough, Langan said.
When that happens, the body can end up holding on to too much fluid, diluting the levels of the electrolytes sodium, potassium, and chloride.
Normally, your kidneys help get rid of excess water by making you have to pee. But during exercise, blood flow is diverted from the kidneys to the muscles, and too much water can become an issue, according to Langan.
“The idea is that you’re drinking fluids with no salt and drinking them faster than you can pee or sweat them out. You dilute your blood,” he said.
Runners tackling a marathon or other endurance event for the first time can be particularly susceptible because their pace will be slow, and they’ll likely take advantage of water breaks along the way, according to Langan.
To help prevent electrolyte imbalances, athletes can add a sports drink or similar supplement to their hydration during or after training, he said.
“For the regular person, it’s really not something you need to be too concerned about. You should consume electrolytes, but beyond what you’re getting in your diet, there’s no need to consume anything extra beyond a sports drink or pinch of salt in your water,” Langan said.
Electrolytes are important even if you aren’t exercising, too. Other potential causes of hyponatremia include excessive alcohol use, certain medications like diuretics, underlying illnesses, or persistent vomiting or diarrhea, which can make it hard to replenish the body’s supply of sodium, according to the Mayo Clinic.
You may want to add more salt and other electrolytes to your water if you notice the following symptoms: