Follow @thegympire from 2008 Olympians Alicia Sacramone and Samantha Peszek! #repost @thegympire ・・・ Isolations #exerciseoftheday This ab exercise is a killer! Shown sped up above the key to performing this exercise correctly is making sure you keep your back flat on the ground and your core engaged! Try two rounds of upper, lower & double - 20 reps in each position!