Lay on the floor with your knees bent. Place a heavy weight on your hips (you can use a pad or folded towel/shirt to protect your hip bones if needed!) Engage your core, squeeze your glutes and lift your hips up toward the ceiling & perform pulses for 20 reps. (These are basically 1/2 reps)

Weight Recommendation:
Beginner: 15-30lbs
Intermediate: 35-55lbs
Advanced: 60-80lbs