Instructions:

1. Adjust the seat of the sled machine so that your knees are at a 90-degree angle when your feet are on the footplate.
2. Sit on the sled machine with your back flat against the backrest and your feet shoulder-width apart on the footplate.
3. Grip the handles on the sides of the seat for stability.
4. Push against the footplate to extend your legs, straightening them completely.
5. Pause for a moment at the top, then slowly bend your knees to lower the footplate back to the starting position.
6. Repeat for the desired number of repetitions.