Why it works: This classic backbend tones your arms, upper back, thighs, and tush.
Get more out of it: To add more definition to your upper body, do backbend push-ups. While in this pose, bend your elbows and lower your head toward the floor, and then straighten your arms. Repeat as many push-ups as you can. To more effectively tone your thighs and glutes, step your feet together and raise one leg in the air.