Lie on your back with your legs fully extended into the air—your body should make an L-shape. Then, reach up with both hands at the same time and touch your toes.

Popple stresses performing every crunch of every rep slowly and deliberately. "It's not a race. The biggest key to this is doing it slow and doing it right. If you go really fast, you don't get as much out of it."

If on your first workout you can do all the reps for all three sets, you're probably moving too fast. "With the guys at spring training, we can usually get through that two times, and it usually takes us three workouts to get to the third set. But some people, if they do it right, they might only get through it once and it might be a struggle just to get there," says Popple.