I've done three centuries this year and have another coming up on the 11th. My on-the-bike pace is usually in the 18 - 19 mph range. Here's what I think I've learned so far:
- Hydration and nutrition are key the four or five days before the ride. I try to increase my ratio of carbs to protein the several days leading up to a century. Lots of complex carbs, low fat, lower than usual protein, and I make sure I get lots of calories. I reduce my intake of diuretics (tea and coffee in my case) and increase my water intake.
- Hydration and nutrition are key during the ride. Eat. Drink. Eat and drink some more. I use GU gel and try to drink more than a liter of water per hour during the ride. When I stop I eat fruit (if available) and anything I can find with simple carbs. Poor hydration and hot weather will lead to cramps at about mile 75 or so, and that makes the last part of the ride a painful experience. I got to enjoy that at the HHH this year.
- Stretch at each rest stop and keep the time spent at stops to a minimum. Getting back on the bike at mile 80 and having tight legs isn't a lot of fun. It's tempting to hang out at the rest stops and visit. You don't need to run through the stops, just take care of your personal needs, thank the volunteers, and get back on the bike.
- Don't hesitate to get off your bike and walk up any really brutal hills. I have friends who are not good climbers who do this. They keep their legs from getting so fatigued and keep their heart rates down in zone two or three, which really helps them once they reach mile 80. A big hill that pushes you into your anaerobic zone takes a lot out of you.
- Don't forget to enjoy the ride. Remind yourself how fortunate you are to be able to take a day and ride at your own pace along a supported route. We're all very lucky to have the health, resources, and time to do these rides, so be sure to have fun.
If you've got 72 hilly miles under you then you should have any problem doing a century if you don't go out too fast. Have fun and good luck.