Air-Pillow Crunch

1. Positioning:
- Start by sitting on the stability ball.
- Walk your feet forward to roll your body down until your lower back is supported by the ball. Your upper back and head should still be off the ball.
- Keep your feet flat on the floor, hip-width apart, with your knees bent at about a 90-degree angle.
- Place your hands behind your head or cross them over your chest. Ensure not to pull on your neck.

2. Starting Position:
- Engage your core muscles. Keep your abdominal muscles tight throughout the exercise.
- Your back should form a straight line from your tailbone to the back of your head.

3. Movement:
- Slowly curl your upper body forward towards your knees by contracting your abdominal muscles.
- Lift your shoulders and upper back off the ball while keeping your lower back in contact with it.
- Hold the crunch for a moment at the top of the movement.

4. Return:
- Lower yourself back down slowly to the starting position, maintaining control and keeping your core engaged.
- Do not let your lower back arch as you lower down.

5. Repetitions:
- Aim for 10-15 repetitions for 2-3 sets, resting for 30-60 seconds between sets.

Tips:
- Focus on using your abdominal muscles rather than pulling with your arms.
- Avoid straining your neck; keep your gaze forward throughout the movement.
- If you feel discomfort in your lower back, reduce the range of motion.

Safety Precautions:
- Ensure the stability ball is properly inflated and stable.
- If you're a beginner, you may want to practice the movement without the ball to master the crunch technique.