Leg Extension Crunch

1. Setup:
- Begin by lying on your back on a mat, with your calves resting on top of a stability ball. Your feet should be flexed, and your knees should be bent at a 90-degree angle.
- Ensure that your arms are crossed over your chest or placed gently behind your head for support.

2. Positioning:
- Keep your core engaged and maintain a neutral spine. Your back should remain flat against the mat.
- Position your legs so that your thighs are perpendicular to the floor, and your lower legs are resting on the ball.

3. Movement:
- Exhale as you engage your abdominal muscles and curl your upper body towards your thighs, lifting your shoulder blades off the mat.
- At the same time, extend your legs out, pushing the ball away and straightening your knees until your legs are almost fully extended.
- Hold this position briefly while keeping your abdominal muscles tight.

4. Return:
- Inhale as you lower your upper body back down to the mat while simultaneously bending your knees and pulling the ball back toward you, returning to the starting position.
- Repeat this movement for the desired number of repetitions, usually 10-15 for beginners.

5. Tips:
- Focus on slow, controlled movements to maximize muscle engagement and minimize the risk of injury.
- Avoid pulling on your neck; use your core to lift your torso.
- Keep your movements smooth and avoid jerking to maintain balance on the ball.

6. Breathing:
- Remember to breathe steadily throughout the exercise, exhaling during the exertion phase and inhaling during the return phase.

Make sure to listen to your body, especially if you're new to exercising, and start with modified versions if necessary.