Note to runners: Ease up on the water. That’s the surprising upshot of new research challenging health experts’ long-given advice for runners and other endurance-sports competitors to hydrate.
 

A growing number of studies suggest athletes are more likely to suffer severe harm by drinking too much during competition than by drinking too little. In extreme cases, people have died after drinking too much liquid during a race, the Wall Street Journal reports. 
 

What’s more, new research suggests that 3 percent dehydration levels during competition, which experts once warned against, don’t hurt performance and might even help it.
 

The latest advice: During competition, drink when you’re thirsty.
 

One study, involving 643 runners in a 2009 marathon in France, found men and women who finished with faster times lost a higher percentage of their body weight during the event than slower runners did. That’s partly because they were not drinking very much — which may give them a competitive advantage without causing any health problems, experts say.