But where do you get the energy from and enough of it to prevent cramping? The answer is carbohydrates.

Sports drinks will always provide the best and most readily available source of carbohydrates.

But according to sports nutritionist Richard Renton, it's the ones with added protein that are thought to have the advantage of improving carbohydrate conversion into glycogen by helping to elevate and maintain higher levels of insulin.

Renton agrees with the beneficial use of protein in sports drinks: