Consistency is the biggest thing you need to think about. My opinion is that whatever you did in practice you should do in the race. By this point, all your long runs over 10 miles should look like the actual race. (Thinking hydration) I drink every 15 min. and gel every 1/2. Works for me because my body is used to it. I only do Gatorade Pro Series for runs over 10 miles. I am not to worried about the sugar, but the sodium content does wonders to keep levels normal. Or close to normal. No cramping at all. Always make sure you drink after using a gel. I use the Gatorade and never have a problem, but once again you have to be consistent in your hydration. Good luck!!!