Instructions:

1. Lie flat on your back with your knees bent and feet flat on the ground.
2. Place your hands behind your head with your elbows pointing outwards.
3. Engaging your abs, lift your shoulder blades off the ground and reach your right hand towards your left knee.
4. Return to the starting position and repeat, this time reaching your left hand towards your right knee.
5. Continue alternating sides for the desired number of repetitions.