If you have a sports drink when you are not doing sport, is it bad for you? I love the taste of them and can’t stop drinking them even when I’m not exercising.
Andrew Goad, by email

Whether you’re exercising or not, isotonic drinks hydrate you quicker than diet drinks and they will give you a small energy boost without flooding your system with too much sugar.

The sugar content of an isotonic drink is between five and eight per cent, which is much less than most soft drinks. The calorie content of most isotonic drinks is 19-30 calories per 100ml compared with, say, Coke, which has 41 calories per 100ml. If you want to hydrate yourself without the calories, though, you can’t beat good old water.