Ab Runners

It's a classic!  Some people call them Ass Burners, but I call them Ab Runners!  If you concentrate on your abs, you'll be working your butt and your core at the same time!

This one is all about speed!  All your weight on one leg, the other one just does a toe touch to the back, while bringing your elbows to your knee.

Remember, concentrate on squeezing your abs while you do this exercise and go as fast as you can!