The Skater exercise works your butt, quads and inner thighs.
For this position, begin with the left foot on the mat, right foot on the glider, slide it back into a lunge and rise up as you pull the belly back. Slide it back, the arms on running position and pull it back. For an alternative variation, slide it out to the side into a squat. Pull it back engaging inner thighs. Slide it out to the side, go nice and deep. Pull it back. 30 seconds on each leg.