Getting visible abs is a goal for many men, and fitness companies cash in—pushing everything from fat-burning supplements to ...

Reverse crunches target the lower abs and tone the lower belly pooch by working the rectus abdominis, transverse abdominis and obliques without neck or back pain.

adding that he himself aims to do a minimum of 500 crunches a day. David also recommended mixing in planks, leg raises and rotational exercises for a well-rounded core workout. And remember ...