Wall Bridge :
Lie on your back with your butt against the wall and arms at your sides. Bend your knees and plant your feet 3 to 4 feet up the wall. Raise your lower and middle back off floor, keeping your shoulder blades on the ground. Hold for a deep inhale, then exhale and slowly return to the starting position.
MAKE IT HARDER :
Cross your right ankle over your left knee so that only your left foot is on wall.
MAKE IT EASIER :
Don't use the wall. Keep your feet flat on floor as you lift into a bridge.