How to do it: Sit on a mat with knees bent, feet flat on floor, hands on backs of thighs. Engage the abs and begin to roll down onto upper back, allowing the feet to lift up. Generate enough momentum to rock back up, focusing on your abs. Come to standing and jump up, twisting body to the left while in air. Jump again, twisting back to center; lower back down to the ground and repeat the sequence on opposite side.
Repeat for 20 to 30 seconds.
Make it easier: Use a hand to help push yourself up off the floor.
Try this move: Rock the Boat