1. Lie on your back.
2. Bring your feet towards your butt so that your thighs form a 90-degree angle with your calves.
3. Raise your butt in the air until your body and thighs are in a straight line. Hold the position for 30 seconds and release.
4. Do 2 series of 20 repetitions.
Alternative: Instead of keeping your butt raised for 30 seconds, alternate by immediately lowering your butt and raising it again.