The front plank is made more challenging by incorporating a dynamic movement. By adding an alternating knee drive, this exercise is noticeably increases its difficulty. Placing the elbows on the fitness ball ensure your core stabilizers are challenged as well. This is a 20 rep set exercise demonstration. This exercise is part of a full length workout video from the mypypeline.com intermediate fitness program, CTX Cross Training Extreme Series, Volume 3, Session 6.