Unilateral Hamstring Rolls using an exercise ball are great for the hamstrings, gluts, abs and back. By using one leg, you're
increasing intensity and challenging your balance and stability.
1. Do it right: Lie on the floor with right heel resting on ball, hips lifted and left leg lifted straight up over hip.
2. Squeeze the hamstring and roll the ball in keeping foot flexed and hips lifted.