The modified roll up is a great exercise for building core strength with no equipment necessary. This move is tougher than it looks, so practice rolling backwards and forwards to get a sense of how much strength and momentum you need to come to the knee. You'll also want a thick mat or carpet to protect your back.
- Start from a standing position and squat down, putting your hands on the floor for balance if needed.
- Roll back, tucking the knees in.
- As you roll forward, using your momentum and core strength, cross the right leg under the left.
- Continue rolling forward (using your hands on the floor to help you up, if needed) until you're in a kneeling position, resting on the right knee.
- From that position, roll back again and, this time, cross the left leg under the right as you come up.
- Repeat, alternating sides for 30-60 seconds.