Lie face down flat on the floor with one or both arms extended comfortably overhead, legs straight, and feet relaxed. Rest your forehead on a towel or opposite arm, or turn your head to one side. Begin with one arm and the opposite leg raised slightly off the ground to provide tension on your deltoids, gluteus, and lower back.
Start with your arm and opposite leg just off the floor, firmly pressing your chest and pelvis against the floor. Raise your arm and leg slightly, to the point where your back is challenged to hold your chest and pelvis down tight against the floor. Hold, continuing to contract your muscles, then slowly lower your arm and leg to their starting positions. Repeat.