Here is an interesting article (Ref BMJ 2012;345:e4737) from the British Medical Journal which discusses the need, or lack thereof, for sports drinks during exercise and endurance activities.
The long and the short if it, according to the article, is that the necessity for sports drinks has been overemphasised by the sports drinks industry. It appears, from the article, that there is not much really relevant research into the relationship between hydration, sports drinks, performance and general health. The conclusions one can actually draw from the research also hinge on the subjects within the tests – real endurance athletes and their sports versus “everyday-Joes” doing 15-30minutes of exercise in the gym.
I guess my take on it is drink some water for activities lasting less than an hour and drink some sort of drink containing some calories and electrolytes when you exercise for more than an hour. It seems to work for me – for rides longer than two hours I tend to consume 200-400kCal per hour depending on what and when I’ve eaten and what training I have planned for after the cycle. Then there are the race-like training sessions where I try and dial in my hydration and nutrition to match race day prep.
Anyway – read the article (and associated comments) and decide what you think. Let me know your thoughts on this. I’m going to try and find some other articles discussing this and if I find any that I think are useful I will post a follow-up.