I have heard pretty much two different theories on the issue of taking gels during training. One that you should take them on your long runs as you would during the race, so on a 20 miler take 2 or 3. The other side says the less you take, the better b/c you are training your body to be more efficient and run on less energy. What do you recommend? Personally, I find that on long runs over 18 miles, I start needing something extra, however I can tought it out all 20 if I have to. Any thoughts? Thanks...