This simple muscle-tightening maneuver is one of the best ways to firm your buttocks and the backs of your thighs. To challenge these large muscles, you have to push your heels down hard. That creates "targeted tension" in the back of your body, but avoids overworking the already strong muscles in the front.
1 Lie on your back and place your feet — only your feet, not your calves — on a sturdy chair or bench. Your bent knees should be directly above your hips, and your shins should be parallel to the floor. Place your arms alongside your body. Keep your head resting on the floor.
2 As you inhale, press down into your heels and slowly raise your hips and lower back off the floor. Pause at the peak of the contraction and exhale while holding up your hips. Focus on pointing your tailbone up toward the backs of your knees. Keep your navel pulled in toward your spine with your abdominals flat. Slowly lower your hips to the floor and repeat this exercise six to eight times.