Start this exercise on your back, placing your hands behind your head.
Now bend your knees and bring them up so your thighs and hips are at 90-degree angle.
Your calves have to be parallel to the ground and your elbows flared lifting your shoulder blades away from the ground.
Now hold this position.
Twist your upper body a direction that brings your elbow to the opposite knee while you fully extend your other leg.
Now hold and return to the beginning position, repeat this in the opposite direction