How to Do a Leg Curl to Work Your Hamstrings

What kind of exercise is this

Leg curls in the machine are an exercise for developing strength and increasing the volume of muscles on the back of the thigh. This muscle group includes biceps femoris, semitendinosus and semimembranosus muscles and is responsible for extension at the hip joint and flexion at the knee.

Depending on the simulator, you can perform the exercise lying down or sitting. In the first option, a person lies with his chest and stomach on pillows located at an angle, puts his shins under the bolsters and bends his legs, overcoming the resistance of the simulator.

In the second, he sits on a chair, presses his knees with one bolster and places his legs straight on the other. Then, holding the handles, he bends his legs, overcoming the resistance of the simulator.

Who should try leg curls in a machine?

This exercise is truly universal. Technically simple and safe, it is suitable for people of any level of training - both beginners and experienced athletes.

For those who want to pump up the back of the thigh

American Council on Exercise calls Leg bending in the simulator is one of the most effective movements for pumping the hamstrings and semitendinosus muscles.

Using electromyography, the scientists measured how hard the muscles tensed during different hamstring exercises. It turned out that only Romanian deadlift on one leg and kettlebell swings can be compared to lying leg curls.

In another experiment this exercise compared with deadlifts on straight legs. Both movements worked the upper hamstrings equally well. But their lower portion, located closer to the knee joint, received almost twice as much load while bending the legs in the simulator.

For athletes who want to protect their muscles from injury

Football players, basketball players, tennis players and other athletes who have to perform sprints with sharp starts and stops often suffer from muscle strain on the back of the thigh.

Risk factors for such injury include, but are not limited to, muscle imbalance. Strong quadriceps on the front side of the thigh and weak hamstrings (the muscles on the back of the thigh) increase the chance of the latter being strained. And strengthening them, both sitting and lying down, reduces their vulnerability.

People who don't want to put a strain on their back

To strengthen the back of the thigh, different variations of the deadlift are often used: classic, Romanian, straight legged. These exercises pump up the hamstrings well, but also provide significant stress on the back extensors.

At the same time, the leg curl in the simulator is an isolated exercise in which only the muscles on the back of the thigh work. With its help, you can safely pump your legs both for those who suffer from lower back problems and for those who already have a significant load on their back and are afraid of getting injured.

What is the best way to do leg curls in a machine - sitting or lying down?

In one experiment checked, which version of the exercise will quickly build muscle on the back of the thigh. Participants pumped their legs on exercise machines twice a week: one group performed five sets of 10 leg extensions while sitting, the other group did the same amount while lying down.

After three months, the scientists measured muscle volume. And those who performed seated leg curls received an increase of 14%, while people who worked lying down received only a 9% increase.

The authors of the study explain this by the fact that in a sitting position, the muscles on the back of the thigh are more stretched and therefore this exercise puts more load on the hamstrings. So, if your gym has a suitable machine, it is better to prefer it.

However, if you do deadlifts on leg day, your hip muscles are already being stressed in a stretched position. In this case, you can additionally load them by bending your legs while lying down.

How to properly perform leg curls on a lying machine

Lie on the machine with your chest and stomach. Make sure your kneecaps are close to the pillow, but not lying on it.

The roller should be located above the heels, in the area of ​​the Achilles tendon or slightly above. If it is mid-calf, adjust training apparatus.

Grab the handles, tighten your abs, and press your body into the pads to ensure core stability. Overcoming the resistance of the machine, bend your knees and bring the roller to touch your thighs. Then, smoothly and under control, return to the starting position and repeat.

How to do seated leg curls correctly

Sit on the exercise chair and place the lower part of your shin on the roller. Adjust its height so that in the starting position your legs are straight, but there is no discomfort in your knees. Check that your kneecap is slightly further than the edge of the chair and that it does not interfere with your bending of your legs.

Lower the support pad to your thighs, above your knees.

Grab the handles on the support pad, push down on the bolster and bend your knees. Smoothly return to the starting position and repeat.

What mistakes should you avoid?

Curling your legs in a machine is a fairly simple exercise, but you can make some mistakes when doing it:

1. Explosive start. In the initial phase of the range, a significant part of the load is taken on by calf muscles. Therefore, if you start moving suddenly and powerfully, the target muscles do not receive enough load. Perform the exercise smoothly so that the back of the thigh has time to work.
2. Sharp return. The eccentric phase, in which you extend your knees back to the starting position, provides a good load. But if you perform the movement too quickly, there will be less stimulus for growth. So do everything smoothly and under control.
3. Rocking up. If in the first phase of the exercise you make a sudden movement with your whole body, fidgeting on the seat or cushions, the target muscles receive less load. To avoid this, hold the handles tightly, tighten your abs, and press your body against the machine.
4. Range Reduction. This is especially true when performing the exercise while lying down: people bend their legs to a right angle at the knees, and then return the roller to its place. This design reduces the time under load and deprives the movement of control. Perform leg curls in the maximum range.

How to Add Machine Leg Curls to Your Workout

Add the exercise to your leg day, and if you are training the whole body without zoning, do it once a week, alternating with other movements on the back of the thigh.

Do three or four sets of 10–12 repetitions. Choose the weight so that each set ends close to refusal - when you feel you can do it a couple more times, but no more.

If your gym has both types of machines - for sitting and lying leg curls, you can alternate them, taking into account the features of the rest of the program. For example, if you've already done Romanian or deadlifts, which work the muscles on the back of your thighs in a stretched position, you can further strengthen them by doing lying leg curls.

If you downloaded hamstrings using Scandinavian crunches or bend your legs while lying down, placing your heels on a fitball, choose a machine for working while sitting.