Lying Straight-Leg Reverse Crunch

1. Starting Position:
- Lie flat on your back on a mat, if available.
- Extend your legs straight up towards the ceiling. Your legs should be perpendicular to the floor and your feet should be together.

2. Hand Placement:
- Place your arms alongside your body. You can keep your palms facing down to provide stability or cross your arms over your chest for a greater challenge.

3. Movement:
- Engage your core muscles. This is important to prevent your back from arching during the exercise.
- Slowly curl your hips off the floor while lifting your legs toward your torso. Your legs should remain straight.
- As you lift, try to keep your knees slightly bent if straight legs feel too challenging at first.

4. Peak Position:
- At the top of the movement, your legs should be lifted as high as possible without using momentum, and your hips should be off the ground.
- Hold this position for a moment, feeling the contraction in your abdominal muscles.

5. Return to Start:
- Slowly lower your legs back to the starting position. Maintain control throughout the movement to prevent slamming your feet down.
- Ensure that your lower back stays in contact with the mat as you lower your legs.

6. Repetitions:
- Aim for 10-15 repetitions per set. As you become more comfortable, you can increase the number of sets.

Notes:
- Keep your movements slow and controlled to maximize muscle engagement and reduce the risk of injury.
- If you're new to this exercise, it may help to perform it with bent knees until you build enough strength to extend your legs straight.