An isolation exercise, seated leg curls allow you to focus intensity on toning just your hamstrings. Because you use a curl machine to do them, they don’t require a lot of technique—the machine helps you maintain your form.

Choose a weight that will enable you to do 8 to 12 repetitions of the exercise.
Sit on the leg curl machine so that your knees clear the edge of the seat and your back is against the backrest. Place your feet over the lower pad, just above the ankles. Bend your knees to a 90-degree angle. Return to the starting position and do 8 to 12 reps.