A. It all depends. Sports drinks or electrolyte drinks are effective at rehydrating as they contain lowish levels of sugars (sucrose plus glucose) combined with electrolytes (potassium, sodium and sometimes magnesium). This combination has been shown to enhance absorption of fluid INTO the body and is superior to drinking water alone.

Half the sugar

At 5 or 6 per cent, sports drinks have around half the sugar content of soft drinks. So they are healthier choice too if you're wanting to keep your sugar intake moderate and if you like the flavour, you're likely to drink more so you rehydrate your body better.

However, having listed their good points, I need to stress that most people do not need sports drinks unless they are exercising at an intense level for more than an hour in hot weather.

Sports dietitians suggest that sports drinks are best reserved for endurance athletes or could be handy for people who haven't had time to eat before training.

Water is still the best and the cheapest fluid replacement for anyone who just does a session at the gym or a jog under 30 minutes.

Sodium intake in sports drinks

The other concern is their high sodium (salt) content which adds to salt already overconsumed by most of us. A 600 ml bottle of sports drink lands you with 150 to 245 mg sodium, which is around 10% of your recommended day's intake.

If you're on a low salt diet or take medication for high blood pressure, steer clear of them.

A better alternative, if you want something with a little more flavour than plain water, is to try the newer sports waters, which are lightly-sweetened drinks (around 1 per cent sugar) with little sodium or electrolytes.

Or dilute down a sport drink by mixing in extra plain water.

The bottom line

Sports drinks are effective as rehydrating drinks as they contain lowish levels of sugars PLUS electrolytes. They are superior to drinking water alone.