5 Leg Curl Variations and 9 Alternatives for a Strong Lower Body

If you want stronger arms, a bicep curl delivers. Yet, if you want to build strength and power in your legs, it requires doing a different type of curl. This is called a leg curl and it can help you and your clients increase your lower body strength.

What Is a Leg Curl?

A leg curl is an exercise in which you bend your knee, lifting your lower leg so your heel moves closer to your glutes (buttocks). This movement can be performed unilaterally, working one leg at a time. It can also be conducted bilaterally, strengthening both legs simultaneously.

Muscles Worked in a Leg Curl Exercise

A leg curl targets the hamstring muscle, which is why it is sometimes referred to as a hamstring curl. Though, technically, the word "hamstring" is used to refer to a group of muscles in the back of the upper leg:

• biceps femoris – outer hamstring; aids in knee flexion, hip extension, and external rotation of the lower leg

• semitendinosus – inner hamstring; aids in knee flexion, hip extension, and medial rotation of the lower leg during knee flexion

• semimembranosus – sits between the other two hamstring muscles; aids in knee flexion, hip extension, and internal rotation of the lower leg during knee flexion

The leg curl exercise also works the glute and calf muscle, even activating muscle in the thigh and shin areas. So, leg curls are a good way to build strength in the entire lower body.

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Leg Curl Benefits

One analysis reports that strengthening posterior muscles can improve mobility better than strengthening anterior muscles. (1) The hamstring is a posterior muscle since it sits on the back of the leg. So, strong hamstrings make it easier to engage in forward-movements such as walking, running, and jumping.

Strong hamstrings also aid in acceleration. This makes strengthening these muscles important for those who play certain sports. Among them are soccer, volleyball, and football.

Other benefits of increased hamstring strength are:

• Better posture. Weakened hamstring muscles can inhibit full leg extension. This can negatively impact your posture. Poor posture can lead to a variety of aches and pains. An unhealthy posture can even hurt your mental health.

• Improved balance and stability. Strong legs improve your balance, making you more stable on your feet. This offers benefits during some exercises, such as unilateral leg exercises. Balance is also important as you age, reducing your risk of falls.

• Reduced back pain. Some studies have connected hamstring range of motion with low back pain. (2) Regularly working your hamstrings improves their function. This can help reduce the chances that you'll develop pain in this area.

When the hamstring is strong, the knee becomes stronger too. That's because this upper leg muscle connects to the knee joint. Add a hamstring curl to your workout and you'll also strengthen your quad, glute, and calf muscle. That makes this a good exercise for the entire leg.

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Why Vary This Curl Exercise?

If the hamstring curl offers all of these benefits, you may be wondering why you would want to vary it. One reason is that the different variations will work the muscle differently.

It's similar to how a bicep curl and hammer curl both work the biceps muscle. However, the bicep curl is better at activating the short head of the bicep. The hammer curl is better at activating the bicep's long head.

Another reason to vary this movement is that you may not have access to a specific leg curl machine. Not all gyms have every type of curl machine created. Some have only seated leg curl equipment. Others have equipment for only the lying leg curl. Then there are the gyms that have no curl machine at all.

Learning the different variations enables you to get a good leg workout in all of these situations. You know how to replace a curl machine with a barbell, for instance. Or you can do the leg curl with no weight at all.

5 Leg Curl Variations

There are five different ways to do a leg curl exercise. On each of these, inhale while bending your knees and lifting your lower leg. Exhale when returning your leg to the starting position. Keep the movement slow and controlled. You can also hold for a count of one or two between the knee flexion and extension if you wish. This will help stress the hamstring muscle a little more.

1. Seated leg curl. You will feel this curl in the hamstring. When doing a seated leg curl, keep your back against the bench. If you can't lift the weight without arching your lower back, it's too heavy. The top leg pads should rest on the lower portion of the thigh. Place the ankle pads above the ankle bones.

2. Lying leg curl. This curl works even more leg muscles, helping to build the shins and calves. You'll also feel it in your glute muscles. To do a lying leg curl, lie face down with the pad between the heel and calf. Straighten your legs completely between lifts. This will help improve your hamstring range of motion.

3. Standing leg curl. One benefit of doing a standing leg variation is that it doesn't require the use of a machine or weights. This bodyweight exercise is good for clients who may not be strong enough to do a weighted leg curl. To do it, stand with your feet hip-width apart. Place all of your weight on one leg, bending the other at the knee and raising the lower leg, bringing the heel closer to your glutes. Repeat on the other side.

4. Valslide leg curl. What makes this exercise so effective at working the hamstring is that it combines hip extension and knee flexion. Plus, like the standing variation, it can be completed without the use of a machine. All you need are a pair of Valslide discs. Lie on your back and place one disc beneath each foot. Raise your hips into the air. Your knees are bent at 90 degrees. Slide your heels out until your legs are straight, without letting your hips touch the ground. Hold for a moment, then pull the legs back in, returning to the starting position.

5. Nordic hamstring curl. This curl is different from many of the others in that, instead of raising and lowering your leg, the leg is kept stationary by holding it at the heel. It involves kneeling on the floor and placing a barbell over your ankles. (A partner can also hold your legs in place if you don't have access to a barbell.) The hamstring is worked by leaning forward at the knee, forcing the muscle to support the forward movement. Research shows that the Nordic hamstring curl improves athletic performance while helping to prevent hamstring injury. (3)

Leg Curl Variations by Equipment

You can also vary the leg curl exercise by using different equipment. Here are the most common.

• Leg curl machine. If you do your workout in the gym, you may have access to a seated leg curl machine or a lying leg curl machine. Some home gym machines have attachments that enable you to do a curl as well.

• Dumbbell. The dumbbell leg curl is a good way to enjoy the benefits of a curl when you don't have access to a leg curl machine. To do it, lie face down on the floor, prop your upper body up on your elbows, and hold a dumbbell between your feet. Lift the dumbbell until each knee is at a 90-degree angle. When first doing this exercise, choose a lighter dumbbell weight. This helps you keep good form while also protecting the lower back.

• Stability ball. You can also work your core muscles by doing a stability ball leg curl. A ball leg curl forces you to engage your abdominal muscles during the curl movement. This also helps build your balance and stability. To do it, lie on your back and place your heels on the stability ball. Your calves should be on the ball as well. Straighten your legs and lift your hips off the floor. Bend your knees and roll the ball closer to your glutes.

• Resistance band. A leg curl can also be incorporated into a resistance band exercise routine. Work both legs simultaneously by attaching the band to a pole or other secure device. Wrap the other end around your ankles while lying face down on the floor. Bend your knees and pull the band toward your buttocks. Another option is to wrap the resistance band around both ankles and lift one leg at a time.

• Suspension trainer. If you have access to a suspension trainer, you can also use this to do the curl. Lie on your back and place your feet in the handles. Straighten your legs as you lift your hips off the floor. Slowly bend your knees and bring the handles toward your glutes.

Where Do Leg Curl Alternatives Belong in a Workout?

If today is leg day (or the day you plan to work your lower body), where does a leg curl alternative belong in the exercise session? 

Normally, it is recommended that you do a multi-joint exercise before a single-joint movement. However, when considering whether to do squats before or after a leg curl, for instance, the main thing to remember is to do your most important exercise first. 

So, if your primary goal is to develop strong hamstrings, the leg curl alternative belongs earlier in the workout. This same approach may also be beneficial for people with an imbalance in this muscle group.

Reasons Someone May Want a Leg Curl Alternative

Some people want an alternative hamstring exercise simply because they don’t like doing leg curls. Others can’t do them because they don’t have access to a machine. 

In the case of the latter, it’s important to find an alternative way to work the hamstring muscles. This makes it possible to build strength in the back of the lower leg even when at a gym that doesn’t have this piece of equipment. It’s also a good solution for people who work out at home or while traveling.

Leg curls may also not be a good option for people with tight hamstrings. When the hamstrings are tight, the leg curl exercise can create discomfort in the knee or back of the leg. If they're excessively tight, they may even tear during this exercise. 

If you or your clients have a knee injury or weakened knees, it may be best to do a different exercise instead. This helps avoid injuring the knee further.

Someone with a hamstring injury might also want an exercise that, while working the hamstring muscles, places less pressure on them. The hip thrust is one example. It does work the hamstrings, but its primary target is the glute muscles.

Obtaining approval from a doctor or physical therapist helps ensure that this movement is safe to do. This health care professional can also make recommendations about whether weight should be used.

9 Leg Curl Alternatives  

If you’re not interested in leg curls at all, or you can’t do them for other reasons, you can swap out this hamstring exercise for something completely different, yet still work the same muscle group. Options to consider include:

1. Donkey kick. This bodyweight exercise helps strengthen the hamstrings. To increase the resistance, do kick the leg while wearing ankle weights. 

2. Glute ham raise. A glute ham raise is like a leg curl in reverse. Instead of keeping your body stationary, only moving your lower leg to target the hamstrings, you keep the lower leg stationary, raising and lowering the rest of the body while kneeling on a pad attached to a frame.

3. Good morning. Another option is to do good mornings. It’s important to use good form when doing this exercise as poor form can hurt the back.

4. Kettlebell swing. In addition to working the hamstrings, this exercise also works the core and upper body. Use control during the swings to get the greatest effect.

5. Reverse lunge. Forward lunges are good for the quads but reverse lunges better target the hamstrings.

6. Stiff legged deadlift. To do this exercise, you bend your knees less than during a standard deadlift. This forces the hamstring to work harder. It also better targets the glutes. 

7. Single leg deadlift. Another deadlift option is to do one leg at a time. This increases the intensity of the exercise.

8. Romanian deadlift. This works the hamstrings, glutes, and adductors, as well as the erector spinae.

9. Glute bridge. This is good for beginner exercisers who may not have a lot of lower body strength. Since the glute bridge doesn't require equipment, it is also easily incorporated into a home workout.

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References

1. Kuo, A. D., & Zajac, F. E. (1993). A biomechanical analysis of muscle strength as a limiting factor in standing posture. Journal of Biomechanics, 26, 137–150. https://doi.org/10.1016/0021-9290(93)90085-s

2. Sadler, S.G., Spink, M.J., Ho, A. et al. Restriction in lateral bending range of motion, lumbar lordosis, and hamstring flexibility predicts the development of low back pain: a systematic review of prospective cohort studies. BMC Musculoskelet Disord 18, 179 (2017). https://doi.org/10.1186/s12891-017-1534-0

3. Clark, R., Bryant, A., Culgan, J.-P., & Hartley, B. (2005). The effects of eccentric hamstring strength training on dynamic jumping performance and isokinetic strength parameters: A pilot study on the implications for the prevention of hamstring injuries. Physical Therapy in Sport, 6(2), 67–73. https://doi.org/10.1016/j.ptsp.2005.02.003