Strengthens: core, butt, backs of legs
Step 1: Lie on your back with your knees bent and one foot flat on the floor. Extend your other leg straight out. Your feet should be in a comfortable position so that you back is flat against the floor (not arched). Experiment with different placements of your feet to find the best fit.
Step 2: Take a deep breath in, expanding into your back and your lungs.
Step 3: Exhale: Keeping your torso in one flat piece, press your foot into the mat and squeeze your butt as you lift your hips up off the mat. Come up high enough that your body makes a straight line from your shoulders to your knees and straight through you extended leg.
Step 4: Inhale and hold your position.
Step 6: Exhale: Come back down to the mat one vertebra at a time.
Image from fitsugar.com
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