My wife and I are training for our first London marathon. She thinks we should be using high energy sports drinks, while I don't. I want to lose weight, and at 15.5 St. and 5'7'2, I have plenty of potential. We always drink plenty of water, before, during and after a run. At the moment we do one long run at 12 miles, one mid-length at c. 5-6 and one at 4 each week.
Very interested in your opinion