Stability ball crunch (full range hands behind head)

Sit on the stability ball with your feet flat on the ground and your knees bent at a 90-degree angle. Place your hands behind your head with your elbows pointing outwards. Engaging your abs, slowly curl your upper body forward, bringing your chest towards your knees. Pause for a moment at the top, then slowly lower your upper body back to the starting position. Repeat for the desired number of repetitions.