Crunches are one of those exercises that everybody seems to have done before. You've probably been doing them since you were just a kid showing off in PE class, right? Well, you may be comfortable with the movement, but you're probably not doing it correctly.
As a matter of fact, the crunch is the exercise I see people screw up most often. Contrary to popular belief, it's actually a fairly advanced movement, and doing it properly takes some thought and some practice.
Ready to up your ab-training game? Then you need this Lifting Lesson!

MARC MEGNA'S LIFTING LESSONS ABDOMINAL CRUNCH 
WATCH THE VIDEO - 4:25