It's a hot day. You've been practising for the marathon. Today's target of 10 kilometers was done in under 20mins. It was a hard run but your mind is upbeat. Your body though is exhausted. Open the sports bag and reach for an energy drink. An hour later, mind and body are in sync, both happy. The same scenario plays out across gyms, tennis courts, cricket pitches or swimming pools the world over. There's nothing like a slug of the coolest energy drink to bring back the pep in record time.

How do these drink work? What is it that's in them that gives you the extra kick? This is where the not so good news begins. Most energy drinks are loaded with sugar and caffeine. Both work to give you a buzz but not without some fallout. Excess sugar is a direct route to diabetes. And energy drinks have mountains of them. But what are more worrying are the caffeine levels. According to research in the United States, energy drinks have levels higher than what is permitted by the FDA, 65mg per 12 oz. The FDA does not regulate these drinks and when tested some had up to 280mg in an 8.4 oz serving. Coffee has 100mg per 6oz so that tells the story. One too many of these drink and you can have a serious caffeine overdose. Symptoms of these include headaches, muscle tension, anxiety, dizziness, tiredness and nausea. The most worrying trend though is that a lot of these drinks are targeting teens and young adults whose body tolerance for caffeine is lower.

So why not drink water. Water hydrates like nothing else does. But the trick lies in the taste. The energy drinks have some great flavours and therefore people tend to drink more of them and hydrate soon but the risk discussed previously do exist. What about other drinks then? Juice? Juice is healthy but not the best for hydration as fruit sugar or fructose actually reduces water absorption so you don't hydrate as quickly. Other carbonated drinks like colas fall in the same sugar/ energy trap that the sports drinks do. Coffee and tea are hydration killers as well as both work as diuretics, which means it causes the kidneys to pull more water out of the bloodstream even as the digestive tries to pull it on to your body. So two steps forward, one step back.

Bottom line? Energy drinks do give you a quick, almost-instant dose of peppiness but they have to be drunk in moderation. With these drinks, it's better to err on the side of caution and limit intake as far as possible. So unless you are in a Wimbledon final or in World Cup Football showdown, reach for the H2O. It's cool, has a hip name and great for your game too!