Beat Boredom with Bike Riding

To lose weight from bike riding, Dr. Ingraham adds, you probably will need to ride harder—something that beginners shouldn't tackle. "Bikes can get a little dangerous the faster you start going," she says. To achieve the equivalent exertion of a 30-minute run, she notes, you might have to pedal for 50 or 60 minutes on a bike. It takes time to build up to that level.

Rhonda Monroe measured her bicycling and health progress by her gradual success on riding up the hills in her neighborhood. "When I first got my outdoor bike, I couldn't make it up the hills. I had to walk the bike at least halfway."

Now, she says, "I can ride up every hill."

For tips on riding safely, go here.