Sit on a leg-curl machine so that your knees clear the edge of the seat and allow for full-range movement of the knee joints. Place the back of your lower shins against the resistance pad or rollers when your knees are straight or slightly bent.

Hold the handles and lean Into the backrest. This creates some slack In the upper tendons, which is helpful if you have tight hamstrings.

 Inhale slightly more than usual and hold your breath as you push your lower legs down at a moderate speed. Keep your toes pointing directly upward as you bend your legs.

 Exhale as you reach a 90-degree angle in your knees, and hold the end position for 1-2 seconds for maximal muscular stress. Return to the starting position under control and repeat for reps.