Eventually, though, Jen started commuting to work on a bike. The trip only took 20 minutes one way, but she started looking—and feeling—healthier. "I really didn't need to kill myself. I just need to do something repeatedly...only after becoming an active person did I know how great it feels to be in decent shape." So don't worry about following a super-structured exercise regimen or a gimmicky tape you ordered from an infomercial during a late-night moment of weakness. Just shake that cement out of your bones.