..according to WebMD:
Exercises for Better Posture
Make these posture-boosting exercises a regular part of your workout. Remember to exhale strongly and pull in your core muscles as you work — a key principle in both Pilates and yoga.
1. Core Stabilizer: Single Leg Extension. This exercise trains your core muscles to work together to stabilize your pelvis.
Starting position: Lie on your back with your knees bent, feet flat on the floor, and hands behind your head. Press your low back into the floor, and curl your head up off the floor.
Action: Exhale strongly and pull your navel in and up toward your spine. Slowly pull one knee into your chest, keeping your low back pressed to the floor, while extending your other leg straight at about a 45-degree angle off the floor. Keep your abdominals pulled in and your low back on the floor. If your low back arches off the floor, extend your leg higher toward the ceiling. Switch legs. Start with five to 10 extensions on each side.
Variations to increase intensity: Double-leg extension: Pull both knees into your chest, then extend both legs straight at about a 45-degree angle, using your core to keep your low back on the floor.
As you extend your legs, extend both arms overhead, reaching in the opposite direction from your legs.
2. The New Crunch. The new crunch works the rectus abdominis and obliques. It’s also called a “curl up.”
Starting position: Lie on your back with your knees bent, feet flat on the floor. Press your low back into the floor. Place your hands behind your head, or reach your arms toward your knees if it doesn’t create too much tension in your neck.
Action: Exhale strongly and pull your navel in and up toward your spine. Curl your head and shoulders slowly off the floor. Hold, then slowly lower back down. Repeat until you fatigue.
Variations to increase intensity: Extend one leg straight at a 45-degree angle toward the ceiling.
Hold both legs off the floor, knees bent, with your shins parallel to the floor.
3. Pilates Roll-Ups / Yoga Sit-Ups. These exercises work the rectus abdominis, obliques, and transverse abdominis.
Starting position: Lie on your back with your legs straight, your feet flexed, and your arms reaching overhead on the floor. Press your low back into the floor.
Action: Exhale strongly and pull your navel in and up toward your spine. Roll up in slow motion, reaching your arms off the floor, then your shoulders and head, rolling up one vertebra at a time until you’re sitting up with your abdominals still pulled in. Slowly roll back down. Repeat three to five times, adding more as your core gets stronger.
Variation to increase intensity: Cross your arms over your chest as you roll up.
4. Crossovers. Crossovers work all the core muscles, focusing on the obliques.
Starting position: Lie on your back with your hands behind your head, your chest lifted off the floor, knees pulled into your chest. Keep your low back pressed into the floor.
Action: Exhale strongly and pull your navel in and up toward your spine. Pull one knee into your chest while extending your other leg straight and rotating your torso toward the bent knee. Slowly switch legs, pulling the other knee into your chest and rotating your torso toward it while extending the opposite leg off the floor. Repeat five to 10 times, adding more as your core gets stronger.
Variation to increase intensity: The closer your straight leg is to the floor, the harder the work for your core. Try extending your leg just inches off the floor, making sure your lower back stays on the floor.
5. Cobra Pose: Back Extension. The cobra pose strengthens the erector spinae and other low back muscles.
Starting position: Lie on your stomach with palms flat on the floor near your ribs. Extend your legs straight behind you, and press the tops of your feet into the floor.
Action: Exhale strongly and pull your abdominal muscles in and up toward your spine. Lengthen out through your spine and slowly raise your head and chest off the floor, using only your back muscles. Do not push down into your arms to press up. Keep your hip bones on the floor, and gaze down at the floor to relax your neck muscles. Slowly lower back down. Repeat three to five times, adding more as your lower back gets stronger.
Variation to increase intensity: Reach your arms long beside your head. Keep your elbows straight.
6. Plank Pose. This exercise strengthens the obliques and transverse abdominis, as well as your shoulder and back muscles.
Starting position: Start on your hands and knees with your palms under your shoulders. Extend both legs straight behind you, toes tucked under, into a position like the top of a push-up. Pull your abdominal muscles in to prevent a “sway-back,” and gaze down at the floor.
Action: Hold the plank until you’re fatigued. Rest and then repeat. Keep your abdominals pulled in and up so your low back doesn’t sag as you exhale.
Variation to increase intensity: Forearm plank: Balance on your forearms instead of your hands.
