How to ...

Do try making your own sports drink. Mix one part water with one part fresh orange juice and a small pinch of salt. If you choose a commercial brand, select one with a little sodium as it enhances fluid absorption in the gut.

Don't assume you have to use an isotonic sports drink (containing particles of easily digestible carbohydrate to boost energy levels) unless you are exercising for at least an hour. Because they are highly acidic, these drinks are harmful to tooth enamel. If you do drink them, do so quickly (or with a straw) rather than sipping over time which prolongs contact with the teeth.

Do clean your water bottle thoroughly after taking it to the gym. A study at the University of Calgary reported high levels of bacteria in water drunk from plastic water bottles that were refilled without being cleaned properly.

Don't drink too much water. It can cause changes in blood dilution that trigger the potentially fatal condition hyponatremia, which affects around 14 runners a year in the London Marathon. Half a litre of water every 30 minutes of intense exercise (more in hot weather) is sufficient.

Do take care not to overdrink after you finish a workout. Wait until you start urinating - a sign that your body is no longer retaining water. When your urine is a pale straw colour, you have drunk enough (this test is not accurate if you take vitamin supplements that change the colour of your urine).

Don't avoid tea, coffee and cola (a favourite with top marathon runners) as fluid replacers. According to studies at the University of Aberdeen, they do not promote dehydration as was once thought and can help to prevent it.

Do weigh yourself before and after exercise to see how much fluid you lose (and therefore how much you need to drink to replace that loss).

Thanks to guardian.co.uk who have provided this article. View the original here.