START:  Start by putting a band around both feet and pull the band up just above your knees. Lie on the floor, face up with your knees bent to 90 degrees, feet flat on the floor or toes pointed up and arms out to your side. Spread your legs apart slightly so there is tension in the band. 

Exercise:  Raise your hips off the ground until your knees, hips and shoulders are all in a straight line. Pause at the top of the lift, then slowly lower yourself back down to the starting position. Keep tension in the band throughout the entire exercise.