Cross body crunch

Lie flat on your back with your knees bent and feet flat on the ground. Place your hands behind your head with your elbows pointing outwards. Engaging your abs, lift your upper body off the ground and twist to bring your right elbow towards your left knee. Pause for a moment at the top, then slowly lower your upper body back down to the starting position. Repeat on the other side, bringing your left elbow towards your right knee. Repeat for the desired number of repetitions.