How to do it: Lie faceup with your knees bent, feet flat on the floor and arms extended overhead, holding the ends of your towel in each hand (your arms should be hovering just above the ground). Pull your abs in tight and lift your hips off the floor into a bridge pose.
Next, extend your right leg out parallel to (but not touching) the ground. Then, bend your right knee and turn your right heel up to the ceiling as you pull your leg in as close to your body as you can without dropping your hips.
Extend your leg back out to your starting position. That’s one rep. Do 10 repetitions with the right leg, and then 10 with the left.
Form tip: As you draw your knee in towards your body, try exhaling and pulling your belly button in tighter to your spine to strengthen the contraction in your abs even more. If it’s too hard to keep your arms overhead, release the towel and press your arms down by your sides for more support.