This exercise looks rather like a reverse push-up and works the back, midriff and thighs as well as the upper arms. Begin with several minutes of walking in place to warm up. Then, sit on the floor with your hands behind you, knees bent and feet firmly on the floor. Use your arms to lift your butt off the floor and lower back down. Repeat this movement for 10 to 20 reps.

Lie on the floor with your arms at your sides, knees bent and heels close to your buttocks. Tuck your tummy and lift your butt up of the ground