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A List of the 6 Best Leg Extension Alternatives to Improve and Maintain Muscle Function

what are leg extensions

Leg extensions. Some people love them. Some people hate them.

You won’t find a lot of in-between amongst gym enthusiasts and personal trainers.

Everyone agrees that leg extensions isolate the quadriceps.

They don’t agree on whether this is good or bad.

If you’re on the fence about leg extensions and think an alternative would be wise, you’ve come to the right place.

We’ll discuss the effectiveness of leg extensions and offer six leg extension substitutes to try instead.


What Are Leg Extensions?

Before we begin reviewing leg extension replacement exercises, let’s establish what the leg extension exercise is and how it is typically performed.

Defined as a resistance weight training exercise, the leg extension is an isolated exercise specifically targeting the quadriceps muscle.

Leg extensions are generally performed on a leg extension machine by lifting a padded lever with your lower legs. If you’re not sure which machine we’re talking about, here’s what it looks like:

leg extension without machine

What Muscles Do Leg Extensions Work?

As mentioned above, the leg extension movement targets the quadriceps muscle — the group of muscles comprising the front of the thigh.

In fact, this exercise exclusively targets your quadriceps. Due to your body’s position throughout the leg extension movement, your quadriceps are isolated.

Your hamstrings and other major leg muscles are not activated during a leg extension.

Are Leg Extensions Effective?

The answer to this question is highly relative and depends on your definition of “effective.”

The answer will also depend on who you ask.

One person may tell you it’s a useless exercise you should avoid completely, while another person will tell you it’s a fundamental part of every leg workout.

Leg extensions can build strength in your lower body and build muscle definition in your thighs. If your goal is to build large, well-defined, quadriceps, then yes, leg extensions can be effective — if performed correctly.

If your goal is to implement a full-body routine to work your body globally (as one unit) and improve overall muscle function to increase lifetime longevity and health — mainstream leg extensions are not effective.

If you’re in the latter camp, we’re glad you’re here. The fitness professionals at In Motion O.C. know the quadriceps are an important muscle group for proper body function.

In addition to the beneficial leg extension variations we’ll introduce shortly, our certified trainers are available for personal consultations.

leg extension substitute

Are Leg Extensions Bad?

The answer to this question is, once again, relative and dependent upon who you ask.

Ultimately, in terms of fitness, our coaches believe that leg extensions are “bad.” They’re especially “bad” if they’re performed incorrectly — which, in our experience, is often the case.

Incorrect use of a leg extension machine might look like:

  • The use of too much weight
  • Completion of too many reps
  • Improper posture
  • Poor hip alignment
  • Using the wrong technique

Beyond technique and improper use of the machine, mainstream leg extensions are an “open-chain” exercise. This style of exercise allows your feet to move freely because they are not planted on the ground.

While this is beneficial when trying to isolate a specific muscle, it can increase your risk of injury.

Furthermore, leg extensions don’t translate into real-life muscle function (why we believe that they’re “bad”) — meaning the motion isn’t replicated in any natural human movement.

Are Leg Extensions Bad For Your Knees?

For those who will tell you to ditch traditional leg extensions, their reasoning will likely be the potential effect on the knee due to constant tension on the ACL.

Extended or improper use of a leg extension machine can lead to knee injuries such as:

The fact is, the aesthetic results of the mainstream leg extension don’t outweigh the risks of a knee injury.

A leg extension machine alternative will allow you to reduce your risk of injury and globally exercise your quadriceps in a more functional way.


6 Leg Extension Alternatives Focused on Improving and Maintaining Muscle Function

There are several reasons you may be looking for a leg extension alternative, including:

  • Injury recovery
  • Injury prevention
  • To avoid the overdevelopment of the quadriceps 

Whatever your reason may be, the goal for the following leg extension alternatives is to work your quadriceps (and supporting muscles, tendons, and ligaments) in a functional way — using movements that reflect the way our bodies move naturally.

An added bonus? With these exercises, you don’t need to go to the gym. You can safely and effectively use these leg extension substitutes, at home.

Leg Extension Alternative #1: Reverse Nordic Curl

The reverse Nordic curl is also referred to as a “natural” leg extension. Meaning you can do this leg extension without a machine.

Follow these steps to complete the reverse Nordic curl:

  1. Kneel on a mat or soft-surface floor
  2. Sit back onto your feet
    • If you are new to this exercise, keep your feet and knees hip-width apart.
    • More advanced? Move your feet and knees just outside your hips
  3. Sit tall, with your hips pushed slightly forward – creating a straight line with the front of your body.
  4. Lean back, lowering your shoulders toward the floor by bending at the knee
    • Keep your hips extended and your core engaged
  5. Continue to lean back as far as you are able to control
  6. Engage the quadriceps to return to your starting position
  7. Work your way up to sets of 10 repetitions

Important things to remember:

  • You may not be able to lean very far back when starting out
  • Do not let your hips drop backward at any point during the movement
    • Your hip flexors will disengage, making the exercise virtually pointless

Why Is the Reverse Nordic Curl a Good Leg Extension Substitute?

We could go on for some time about the benefits of the reverse Nordic curl.

But, to keep it simple, this exercise is a good leg extension alternative for several reasons:

  1. It develops strength in all four of the quadriceps
  2. It increases mobility of the hip flexor
  3. It reduces the risk of injury during rapid muscle movements such as running
  4. You can do these quad extensions at home

Leg Extension Alternative #2: Bulgarian Split Squat

A basic Bulgarian split squat requires only a bench or stable chair, making this another way you can do an effective leg extension without a machine.

  1. Stand facing away from your bench, about two feet away
  2. Engage your core, push your shoulders back
  3. Standing straight, put your left foot on the bench behind you
    • You can flex your ankle and rest the ball of your foot and toes on the bench OR put the top of your foot flat on the bench
    • This foot is only extended for balance—the movement and engagement is all in your front leg
  4. Bend your right knee into a single leg lunge
  5. Push back to standing, using your right foot
    • Your left quad and glute will also engage in this upward motion
  6. Repeat with your right foot on the bench behind you

Why is the Bulgarian Split Squat a Good Leg Extension Alternative?

In addition to working the quadriceps, this exercise will also target your hamstrings, glutes, abs, and calves. Plus, this is another leg extension exercise without a machine.

The balance required for the Bulgarian split squat activates your core and upper body — helping you keep proper form and create a movement that engages your full body.

leg extension substitute

Leg Extension Alternative #3: Reverse Lunges

Reverse lunges implement a leg extension movement similar to the Bulgarian split squat — without the balancing act.

  1. Stand tall, feet hip-width apart, hands on your hips
  2. Step back with your left foot (about two feet, more if you’re comfortable)
  3. Lower your hips toward the ground so your front thigh (right) is parallel to the floor
    • Your knee should be directly above your ankle
  4. Return to a standing position
    • Press your front (right) heel into the floor, bringing your left leg forward
  5. Repeat, alternating the leg that steps back

Why Are Reverse Lunges a Good Leg Extension Substitute?

Reverse Lunges will give you the quadriceps workout your legs need while also:

  • Improving muscle imbalance
  • Increasing your stability
  • Building your glute muscles
  • Reducing hip and knee pain

Leg Extension Alternative #4: Step-Ups

Step-ups may not look like much, but add weights or reps once you’re comfortable and you’re sure to see — and feel — an improvement in your lower body strength.

  1. Find a step or bench that is at or just below your knee level
  2. Place your entire left foot onto your bench
  3. Step onto the bench, bringing your right foot to meet your left
    • Be sure you are pressing through your left (forward) heel in the upward motion
  4. Step down with your right foot, follow with your left to return to your starting position
  5. You can alternate leading legs between each rep (for novices) OR complete one set of 8-12 reps with the same leading leg, then switch

Why are Step-Ups a Good Leg Extension Alternative?

Step-ups strengthen all the muscles we use daily to climb a set of stairs.

By adding Step-ups to your routine, you’re improving the function of every muscle group you engage during a common daily activity.

This leg extension substitute is also great for the glutes — and who wouldn’t welcome some improvement there?

Leg Extension Alternative #5: Sandbag Squats

There are several variations of a sandbag squat, but the most simple to perform is the bear hug sandbag squat:

  1. Stand with a large sandbag between your feet
    • 50% of the bag should be in front of you and 50% behind you
    • Your feet should be wider than hip-width and facing slightly out
  2. Bend at the hips, keeping your back straight, scoop your hands under the sandbag
  3. Explosively drive up, hugging the sandbag to your chest with your arms wrapped tightly around it
  4. Stand up tall and lock your shoulder blades down and back
  5. Descend into a squat, keeping your body upright
  6. Raise your body back up and repeat squats through your desired rep count

Why are Sandbag Squats a Good Leg Extension Substitute?

Sandbag squats are a quadriceps extension exercise that engages your entire body.

Bear Hug Sandbag Squats:

  • Improve daily posture  
  • Develop core strength
  • Fortify the muscles in your lower back

what are leg extensions

Leg Extension Alternative #6: Standing Leg Extension

This standing leg extension substitute offers a similar movement as a leg extension machine but changes the exercise from an “open-chain” exercise to a “closed-chain” exercise — meaning your supporting leg and foot are in a fixed position:

  1. Stand with your feet about hip-width apart with your hands on your hips
  2. Tighten your core and raise your left foot slightly off the floor
  3. Send your left foot back by bending your left knee
  4. Extend your left leg in front of you by straightening your left knee
  5. Keep your quadriceps and abdominals engaged throughout
  6. Complete 8-12 reps and repeat with your right leg

This exercise can easily be modified for more exertion with ankle weights or resistance cables.

Why is a Standing Leg Extension a Good Alternative?

While a traditional leg extension exclusively targets the quadriceps, the standing floor extension exercise also targets your core.

Additionally, your balance and coordination will also be challenged, both of which improve overall muscle function.

Looking for Guidance on the Best Leg Extension Alternative for Your Body? Consult with In Motion O.C.

In Motion O.C. provides an intimate alternative to large, impersonal gyms. We value and prioritize our relationships with our members.

We focus on teaching members how to maximize workout routines to enhance their overall health and wellbeing rather than simply “getting those gains.”

What’s more, our fitness coaches and physical therapists work alongside one another to ensure your health is optimized. Contact us today for a free consultation.

leg extension substitute

In Motion O.C.