Before the race I sipped on water. It was a humid morning in which I wanted to hydrate before I began running since it was supposed to warm up so much later on. The course had water and gatorade stations almost every mile. They were both available to pick from. I switched on and off every mile. If I drank water at the first station then I grabbed a cup of gatorade at the next one. After a few hours of running when temperatures reached 87 degrees, I took water more often to not dehydrate.
I have been running with Gu for years now. It has always worked for me. I use it in training runs and in races. It's really a preference for what works for you. I know there are numerous other kinds out there such as Hammer gels, Clif shot blocks, sports beans, etc. I have tried other brands but they were not as good or didn't work right.
Here is the breakdown:
Miles 4, 8, 12, 16, 20, 24 - I took one Gu chomp every four miles. I took two packets of chomps with me but had some left over. Each packet contains 8 chomps which says that will fuel between 1 and 1/2 to 2 hours worth of running. If I felt I needed more (hunger or running low on energy) I would take another or take a Gu gel.
Mile 17, 20, 23- One of my friends ended up running a marathon a couple weeks before I did. She suggested I buy salt tablets to help against leg cramping since she cramped up during her race. I found them at the expo. My dad told me to begin taking them at mile 17 even if I didn't feel that I needed them because it would help later on if something were to happen. I took one every three miles towards the end and never cramped.
Different races call for different types of fueling. During a half marathon I would only take two to four chomps. During my most recent half I only took two. For my next race/ long training run I am thinking I will either run without anything or try a different brand since Gu chomps and I aren't getting along too well.. but I don't have another race for a couple more weeks.
What works for you?