For relaxation and restoration, all yoga poses are not created equal. Inversions -- any pose that gets your heart or feet above your head -- have an "amazing capacity to enliven your body, mind, and spirit," says Stan Woodman, yoga teacher trainer and co-owner of Kaia Yoga in Greenwich, Connecticut. They may even strengthen your disease-fighting capabilities by improving the flow of lymphatic fluid.

Give the following poses a try and watch your outlook -- and your health -- turn around.

Try It When: You've got an upset stomach, constipation, bloating, or gas Why Releases tight hip flexor muscles, which can constrict the digestive organs. Calms the nervous system and relieves stress.

Why: Releases tight hip flexor muscles, which can constrict the digestive organs. Calms the nervous system and relieves stress.

How to Do It: Lie on your back with knees bent into chest. Lift your hips and place hands on the lower back with fingers pointing up, resting hips on hands. Straighten legs until your toes are over your eyes. Hold one minute. Remain here or continue to Plow. To get into Plow, bring legs over your head until toes rest on the floor. Press thighs up toward the ceiling and gently bring your hips back over your shoulders. Hold one minute.

Try It When: You can't sleep

Why: Calms the nervous system, quiets the mind, and releases tension from the feet, backs of the legs, spine, shoulders, and neck. (This is the inversion most recommended for pregnant women.)

How to Do It: Sit on the floor with your right hip and shoulder close to a wall. Lie down on your left side, then roll on to your back and extend legs straight up to rest on the wall. Place arms on the floor at your sides with palms up. Use a folded blanket under your hips for added lift and a slightly more intense inversion. Relax here for up to 10 minutes.

Try It When You've been sitting all day -- at your desk, in a car, or on a crowded flight Why Boosts the flow of blood from the feet to the heart and quiets the mind. Also frees the hips and lower back, which bear the brunt of too much sitting. How to Do It Lie on your back and place your lower legs on a chair, stool, or low table so your shins are parallel to the floor. Lay your arms on the floor alongside you with palms facing up. Close your eyes and rest for up to 10 minutes.

It's known as the King of All Poses because it tones your entire body, nourishes your abdominal organs, and boosts your immunity. But most of us need to work our way up gradually. The three poses below will prepare you well.

Dolphin Plank

What It Does: Improves shoulder and core strength

How to Do It: Start on hands and knees. Place forearms on the floor and walk feet back until head, shoulders, and hips are in one even line. Align shoulders over elbows and look down at your hands so your neck stays long. (When you can hold any of these poses for 10 breaths, you're ready for the next step.)

What It Does: Builds confidence in the pose

How to Do It: Start on hands and knees with toes touching a wall. Clasp hands and use forearms for support as you put the crown of your head on the floor. Straighten legs, lift hips, and put one foot on the wall at hip height, then follow with the other. Hold for 10 breaths.

What It Does: Allows you to practice balancing on your head

How to Do It: Interlace fingers and put the crown of your head on the floor, cradled in clasped palms. Lift hips and walk toes toward your head, then slowly lift one leg at a time, keeping knees bent into your chest. Hold for up to 10 breaths.

What It Does: Strengthens core, back, legs, and arms, and calms the nervous system.

How to Do It: Once you can balance comfortably in egg-shaped headstand, extend your legs. Most of your weight should be on your forearms and not on your head. Hold for a few breaths and work your way up to three minutes in this position. Come down by bending knees into chest, then lowering one foot at a time to the floor.