From kneeling, place your right leg in front of you. Do not let your knee go past your ankle. Keep your torso upright, and press your hips down and forward towards the ground. You should feel the stretch in your hip flexor muscle (psoas)--the area where your hip meets your legs. You can pulse in the stretch or just hold it. Repeat on the left leg.
Why it works
Surprisingly, hip flexibility can help cure back problems. Also, flexible hips keep you agile so that you can burn more fat and calories!