No sweat: Are sports drinks worth the money?
Shaun Daley / Alamy By James Witts It’s hydrating, packed full of sugars and contains electrolytes vital for cell function. Which is why, until the mid-20th century, beer was considered the sports drink of choice – especially as it was safer to drink than tap water. Today, sports drinks have taken on a very different flavour. And if you believe the advertising, working out without one will lead to dehydration, impaired performance and a deep sense of self-loathing. But should we believe the hype or are the ads peddling more spin than the Tour de France? One of the big claims for sports drinks is that they are rich in minerals like sodium and potassium that dissolve in bodily fluids to create charged ions vital for cell function, while also replacing fluids lost through exercise. On the face of it this makes sense. When you sweat, you lose water from blood plasma. This causes a drop in blood volume, meaning your heart has to work harder to deliver much-needed oxygen to muscles. How big a problem is this? When exercising, an average person sweats between 0.8 and 1.4 litres per hour. The International Olympic Committee reviewed the studies and concluded that performance is likely to be impaired by dehydration if someone loses 2 per cent of their body weight or more through sweating – 1.5 litres for someone weighing 75 kilograms. So do you need to drink?