Sports drinks have enjoyed a huge surge in popularity in recent years. You rarely see anyone exercising these days without one in their hand.
Yet recently the Times newspaper in the UK reported that some research promoting the value of rehydration had been paid for by that internationally famous rehydrater, Coca-Cola.
And the Guardian reported that Professor Tim Noakes at the University of Cape Town argues that over-hydration is the real problem, partly driven by the drinks industry.
"Most people probably aren't going to become carbohydrate- depleted in a short moderate-intensity gym session," Corbett says. "If you haven't had time to get a meal then a sports drink will give you a quick boost of energy, but there are possibly better ways of doing that." Moreover, if you're exercising to lose weight, a sports drink may even be counterproductive. "Negative calorie balance is what you want if you want to lose weight," Corbett says. "I see it myself. People at the gym walking while consuming these high-energy drinks. Potentially, they could be consuming more calories than they're burning off."
