Tweeting that her water tip of the day is that she drinks five to six liters of water a day, Khloe Kardashian touched off a bit of a health storm. Even though she added that this amount was recommended by her nutritionist and based on her body weight and workout regimen, some Twitter followers found Khloe’s water intake excessive.

We tend to drink too little water, which is why hydrating is standard advice on every top ten list of how to get healthier. But overhydration, also called hyponatremia, has emerged for years as a problem among marathon runners who overhydrate during a race to the point of putting themselves in danger. The conventional wisdom used to be that an endurance athlete needed to drink water in order to prevent weight loss during an event, but more recent research brings that into question. Sports drinks with electrolytes tend to be safer, but they still mostly contain water and you should be careful not to drink too much. By the end of the race, marathon winners typically are dehydrated and have lost weight, and they rehydrate afterward.

If you don't work out, some studies shed doubt upon needing more than about nine cups of water, roughly two liters. The intestines can absorb only a little more than 20 fluid ounces every hour. 

One respected expert on hyponatremia, Dr. Tim Noakes, says that the only real symptom of dehydration is thirst, and he recommends following the simple rule of drinking when you’re thirsty. Symptoms in healthy people associated with hyponatremia include disorientation, confusion, headache, muscle weakness, nausea and vomiting. If you experience any of these symptoms while you’re in an endurance run or workout, consider whether you’re drinking too much.

Sources: healthline.com, running.competitor.com, runnersworld.com