How To: Do the "abs matrix" runner's ab workout

Professional trainer Joel Harper shows us how to do the "abs matrix" a runner's abs workout.

-First, you are going to want to grab some weights.
-Balance on one leg, lean back, and press the weight upwards.
Beginners: 6-10 reps
Advanced: 11-15 reps
-You may feel the urge to roll forward, but remember to lean back.
-You alternate each arm/weight.
-Remember to repeat while standing on your other leg.
-Also remember to pull your stomach in and use your lower abs.
-When pushing the weights up, make sure you aren't pushing them forward.

There you have it, some instructions and a couple tips on how to do the "abs matrix."