Forget crunches. The V-up takes your abdominal workout to the next level. Orthopedist and fitness trainer Dr. Levi Harrison, who produced a DVD, "The Art of Fitness Cardio Core Workout," shows how to work up to this advanced move in stages so you don't strain your lower back.
What it does
This intense move challenges all of the muscles in your core — front to back.
What to do
Start by lying down flat with your legs long, abdominals tucked in and back pressed into the floor. Extend your arms behind your head on the floor.
In one fluid motion, bring your arms and legs up like a jackknife, reaching your hands between your legs and just past them. Lower your arms and legs to start. Repeat.
Beginners should work up to this move, by first bending your knees slightly on the mat and reaching your outstretched arms to your knees in a sit-up.
Once you have mastered the sit-up, try raising your legs from the floor into a tabletop position above the ground at the same time you bring your arms in to touch your knees.
Then, when you're feeling strong, try to raise straight legs to the ceiling at the same time you raise your arms to touch your toes. Only when you have mastered this move are you ready to try reaching between and beyond your legs. For the most intense variation, try adding a medicine ball of 2 to 10 pounds.
Do two sets of five repetitions, working up to three sets of 10 or 15.