butt-ups

How to do it

1. 1Lie flat on your back with your knees bent and feet flat on the ground.
2. 2Place your hands by your sides, palms facing down.
3. 3Engaging your abs, lift your legs off the ground, bringing your knees towards your chest.
4. 4At the top of the movement, squeeze your abs and pause for a moment.
5. 5Slowly lower your legs back down to the starting position.
6. 6Repeat for the desired number of repetitions.