Set-up: To begin the sit-up start with feet flat on the ground and knees bent. Hold a medicine ball with both hands and extend your arms straight above your chest (so the ball is directly over your shoulders).
Movement: Contract your abdominals and raise your trunk up until it is vertical or nearly vertical to the ground. Keep the ball overhead (arms straight) as you sit all the way up. At the top, your torso should be vertical with the medicine ball still overhead—arms aligned with your ears. Lower yourself under control and repeat. Do not use your arms to flex forward and cheat the exercise.
Caution: Note that traditional full-range sit-ups involve repeated flexion of the lumbar spine which can cause issues over time. If you have any preexisting concerns in the lumbar spine, consider if other similar exercises might provide a better safety profile.
