Exercise ball supine triceps extension

Sit on an exercise ball with your feet flat on the ground and your knees bent at a 90-degree angle. Hold a dumbbell with both hands and extend your arms straight up towards the ceiling. Slowly lower the dumbbell behind your head, keeping your elbows close to your ears. Pause for a moment, then raise the dumbbell back up to the starting position. Repeat for the desired number of repetitions.