Need some advise. I commute to work about 2,500 miles a year. My riding is in 1 hour intervals (17 miles each way around, 17 mph average). Lately, I have been adding to this with a Saturday morning club ride (40 to 70 miles) on my race bike. I do great the first 40-50 miles, taking turns on the lead, but lose energy the last 10-20 miles. Yesterday, I sorta-bonked at 51 miles with 7 more hilly miles to go. My speed was off the pace of the group. The group was nice enough to pull me in twice and I finished with the group. I had only consumed 1 water bottle during the ride. It was a cool morning and didn't feel the need to force down more water. I suspect my problem was either dehyrdation, or glycogen depletion. Probably the later. Any suggestions would be appreciated. Should I use a sports drink, or gels. I usually stay away from that stuff (too sugary), but I think it might help in this situation.