It's obviously important to stay hydrated while exercising. But sports medicine physicians and Loyola University in Chicage found nearly half of runners surveyed drink too much water or sports drinks during races, believing it's necessary to replace lost sodium. In fact, low sodium in runners is usually caused by drinking too much, which dilutes the blood's sodium content. The message: only drink when thirsty. When you do, consider a glass water bottle with a no-slip silicone sleeve by bkr — as functional as it is adorable.