It's not only the amount of weight you lift or your technique that can help improve your problem areas. These simple strategies can make a saggy butt and belly bulge disappear.

Use A Foam Roller

These long tubes are perfect for loosening up tense spots-inhibiting too-strong muscles and activating too-weak ones-which helps you work the intended muscles more effectively. Try this stretch to release your piriformis, along your outer hip (it will improve your glutes' ability to contract): Center the left side of your butt on a roller, place your hands on the ground behind you, and cross your left leg over your right knee. Lean slightly to the left on the roller until you find the most tender spot. Hold for 30 seconds to 2 minutes or until it's no longer tender, then switch sides and repeat.

Improve Your Posture

Strengthening your back and core muscles and stretching your chest will help you stand straighter and look slimmer. Pilates, which teaches you to pull your navel toward your spine, is atop core booster, and fans often rave about how they feel taller and have flatter abs after just a few sessions. Once you get the hang of pulling in your belly button, you can use the technique throughout the day to activate your middle muscles. Throw in a few back moves to help you keep your shoulders down. At the office, stretch at your desk to release those supertight chest muscles.

Pick up Shape's special Make Over Your Body issue for complete details about this 21-day plan. On newsstands now!