The key to bodyweight exercise is mixing it up. Challenge yourself. If you're not sore the next day, you didn't work out hard enough. "When you push yourself, you'll be building muscle, increasing bone density, strengthening ligaments, and burning calories for up to 36 hours after your workout," says Mark Lauren, author of 'You Are Your Own Gym.' When push-ups become too easy, switch to a different grip – wide, narrow, or staggered hands – or pause during the motion. Try one set on an incline, the next on a decline, and the next with one hand on a basketball. For all of the exercises below, aim for three sets of 10 reps unless noted otherwise. Time yourself and try to do them more quickly the next time around. If you can't finish a set, complete it with the easier version.
The No-Weights Workout: Dips
When doing dips, push up with your core and glutes, not just your arms. Lean forward to work more of your chest muscles; lean back to work your triceps.
Make it Hard
With your hands on the backs of two chairs, slowly lower until your chest reaches your hands, then push up. Keep your back straight.
Credit: Photograph by John Loomis
With your hands next to your butt on a bench and your feet out front, lift your body, supporting yourself only with your hands. Lower almost to the bench; push back up.