I usually ride for 2 hours when I ride. There are always at least one hill in the ride if not 2 or 3. I usually eat normally before and after riding, nothing special. I drink water while I ride and usually finish one water bottle on a 2 hr ride. The other day I thought I was doing fine but when I went up a hill I noticed my left shoulder tense up and ended up with a head ache before the ride was over. I do suffer from migraines but not as often as I do when I ride.