V-Up Roll Up

Performed in a 4-count cadence, this exercise is most commonly known from P90X's Ab Ripper. Start by lying flat with your arms extended above your head. Do a full sit-up and touch your toes. As you are returning to the starting position, when your mid-back hits the ground, begin to raise your legs to a 45-degree angle and hold them there. Crunch up and touch your toes while keeping your legs in position.