The condition called exercise-associated Hyponatremia is a serious health risk that has killed 14 football players and marathon runners, University Herald reports. This is due to excessive liquid intake of water and energy drinks during training and competitions.

Drinking too much water dilutes sodium in the body and overwhelms the kidneys, which leads to damaging of cells. Severe cases of exercise-associated Hyponatremia can lead to death.

Symptoms include dizziness, nausea, vomiting, and headache, to more serious effects such as mental state shifting, seizure, and coma.

According to researchers at Loyola University Health System, people should only drink water when they are thirsty and not until their urine turns clear.