If you have never ridden 100 miles on a bike before, you have no idea (a) how good it feels, nor (b) how difficult it is. Nor do you realize how many billions of calories you'll burn in the process. For those who haven't, the annual Everglades Snowbird Century is a great place to begin. Scaredç Don't be: It's a ride, not a race, and if you think your legs will fail long before your resolve, sign up for the less demanding 25, 41, or 62-mile options. For a $35 registration fee — $5 of which is donated to Everglades National Park — riders travel the rural roads of Miami-Dade County from a vantage point like no other. The route is clearly marked, and every 20 miles or so, participants can stretch out and chill out at rest stops stocked with an array of water, sports drinks, fruit, and bagels. Technicians volunteered by local bike shops are but a phone call away should you experience mechanical problems, so the only thing for you to do is ride. And though you might not realize it at the time, this will probably be the most physically strenuous activity you will ever accomplish. And your ass will never have looked so good.