13 Best Leg Extension Alternatives for Quads Size and Strength

Leg extensions are a very popular exercise. Unlike the squat, lunge, and leg press, the leg extension is an isolation exercise, which means they involve movement at just one joint instead of several. This exercise targets your quadriceps or quads for short.

The quads consist of four muscles:

1. Rectus femoris
2. Vastus lateralis
3. Vastus medialis
4. Vastus intermedius

All four quads work together to extend your knees, and the rectus femoris, working with the iliopsoas, also flexes your hip.

While you can get a good quads workout from compound exercises, it’s often useful to target these muscles with leg extensions. This is especially true if you feel your quads are lagging behind your glutes and hamstrings, which are the other muscles involved in most compound leg exercises.

But, what if you train at home or in a garage gym and don’t have access to a leg extension machine? Or find that leg extensions cause knee pain? Maybe your gym doesn’t have a decent leg extension machine, or you just dislike this exercise…  

The good news is that there are plenty of exercises you can do instead. Some replicate leg extensions using different equipment, while others work your quads using alternative movements. Either way, these exercises will build and strengthen your quadriceps.  

Here are the 13 best leg extension alternatives for stronger quads.  

1. Kneeling leg extensions

Also known as natural or bodyweight leg extensions, this simple exercise is ideal for home workouts. All you need is space to kneel down. This quads-builder can be hard on your joints, so introduce it gradually into your workouts and skip it entirely if it causes knee pain.

How to do it:

1. Kneel down so that your femurs are perpendicular to the floor. Use a mat or folded towel to protect your knees. Cross your arms in front of your chest.
2. Without flexing your hips, sit back and lower your butt toward your feet. Go back as far as your flexibility and knee health permit.
3. Return to the upright position and repeat.
4. Make this exercise harder by holding a weight to your chest or raising your arms overhead.

2. Dumbbell leg extensions

No leg extension machine? No problem! Work your quads with this old-school alternative. All you need is a dumbbell and a weight bench or chair. Place a mat under the dumbbell so that, if you drop the weight, you won’t damage the floor.

How to do it:

1. Sit on your bench or chair with the back of your knees level with the end of your seat. Place a dumbbell between your feet and grip it tightly.
2. Extend your legs until they’re straight.
3. Bend your legs and repeat.
4. You could also do this exercise while wearing ankle weights.
5. Using a low bench/chair will limit your range of motion. Raise your seat on blocks to start each rep with more bend in your knees.

3. Cable leg extensions

This leg extension variation involves hip extension AND knee flexion, which produces a very intense quads contraction. You won’t be able to go especially heavy with this exercise, but you’ll DEFINITELY feel it working the target muscles!

How to do it:

1. Put on an ankle cuff and then attach it to a low pulley cable. Stand with your back to the machine.
2. Raise your leg, so your hip is roughly level with your knee. Brace your abs. Use your arms for balance as necessary.
3. Without lowering your knee, extend your leg and then bend it again.
4. Try to do the same number of reps on each leg.

3. Short step lunges

Lunges are a fantastic leg exercise. You can read all about them in this in-depth guide.  Lunges can be modified to make them more quad-centric. Just shorten your step to increase the range of motion of your front knee, increasing quads activation.

This modification can be done with or without weights and works especially well in conjunction with blood flow restriction (BFR) training. However, it also puts more stress on the front knee joint, so avoid this exercise if you have a history of knee pain.

4. Sissy squats

Despite their name, there is nothing effeminate about sissy squats. In fact, this old-school bodybuilding exercise is really tough! Sissy squats hammer your quads but can also be hard on your knees. But, if you’re looking for a good way to finish your leg workout, a few sets of sissy squats could be exactly what you need. You can do sissy squats with or without weights.

Check out sissy squats article to learn how to do this classic exercise.

5. Barbell hack squats

Quads exercises don’t come much more old-school than barbell hack squats. Named after old-time wrestler and strongman George Hackenschmidt, this movement is challenging but rewarding. While you CAN use a hack squat machine, if you don’t have one available, you can get the same quad building effect from this exercise.

Check out this hack squats guide to discover how to do this thigh building exercise.

6. Front squats

While all types of squats involve your quads, front squats increase quadriceps activation. Done with a relatively upright torso, front squats involve less hip movement and more knee movement than back squats, making them more quads-centric.

You can work your quads even harder by placing weight plates under your heels. However, this strategy may also put more strain on your knees, so use it with care.

Learn how to do front squats here!

7. Bulgarian split squats

Bulgarian split squats are another compound leg exercise that involves a lot of quadriceps activity. You can make them more quads-centric by using a slightly shorter stance and keeping your torso as upright as possible. You can do Bulgarian split squats with weights, but it’s also a very effective bodyweight exercise. Do high reps with short rests and use it to chase the pump!

Read our complete guide to Bulgarian split squats to learn how to do this awesome exercise.

8. Smith machine squats

Smith machine squats are a divisive exercise; some people love them, and some people hate them. The haters say things like “they aren’t functional,” but what if you aren’t interested in increasing strength and performance? What if the only thing you care about is building bigger legs? In that instance, Smith machine squats can be hugely effective.

With no balance to worry about, you can move your feet to target different leg muscles. A narrow stance with your feet only just in front of your hips is especially good for hitting your quads. And, because you don’t have to worry so much about getting stapled by the weight, you can do Smith machine squats to failure and in relative safety. Just remember to set those safety catches!

Learn more about Smith machine squats in this guide.

9. Cyclist squats  

Top cyclists are often renowned for their phenomenal quadriceps development. There is a lot to be said for cycling up mountains in your quest for bigger quads. However, you don’t have to go to such lengths if you don’t want to. Try cyclist squats instead!

This exercise involves using a narrow stance, an upright torso, and raising your heels on blocks. You can do front, back, dumbbell, or goblet cyclists squats as preferred, or just use your body weight. Remember, though, that raising your heels increases knee joint stress, so take care with this exercise if you have a history of or experience any new knee pain.

How to do it:

1. Using your preferred method of loading, place your heels on a 3” block and stand with your feet no more than hip-width apart. Brace your abs.
2. Keeping your torso as upright as possible, squat down as deep as you can. Take care not to round your back.
3. Push through the balls of your feet and return to your starting position.

10. Step-ups

Step-ups are a very underrated quads exercise. A lot of people dismiss them as a cardio move – thanks, step aerobics! But, if you use a knee-high step and some extra weight, the humble step up is a great quads builder that can help you fix left to right strength imbalances and improve your coordination and balance.

The key to successful step-ups is NOT pushing too hard with your trailing leg. Instead, the raised leg should be the one doing most of the work. REAL steps are more like a one-legged squat when you do them this way.

Read more about step-ups here.

11. Lateral lunges

A lot of people view lateral or side lunges as a glute/abductor/adductor exercise when, in fact, they’re also a very effective quadriceps exercise.

Lunging sideways puts more stress on your working leg than forward or backward lunges, especially if you do all your reps on one side before switching. Lateral lunges can be done with just your body weight, or with dumbbells or a barbell.

Learn how to do lunges here.

12. Constant tension leg presses

You can apply the constant tension method to almost any leg exercise, but it’s especially effective (and safe) during leg presses. Constant tension involves stopping your rep just before lockout so that the weight you are lifting is never supported by your bones.

This makes your chosen exercise much harder as you don’t get any rest between reps, and blood and lactic acid will soon start to pool in your quads, producing a muscle-building pump.

How to do it:

1. Sit on your leg press machine and unrack the weight as usual. Position your feet, so they are no more than hip-width apart and a little lower on the footplate to maximize quads recruitment.
2. Bend your legs as far as you can without rounding your lower back.
3. Without pausing or bouncing at the bottom, drive the weight back up but stop a few inches below lockout. Your knees should be slightly but noticeably bent.
4. Lower the weight and repeat.
5. This exercise works best done for moderate to high reps with medium to light weights. Sets of 20-30 reps are especially pump-inducing!

13. Backward sled drag

Weighted sleds are often viewed as conditioning or fat burning tools. And while they do provide an excellent low-impact cardio workout, you can also use a sled to build muscle and strength. While dragging a sled forward works your glutes and hamstrings, walking backward as you drag a heavy weight really hammers your quads.

People with sore knees often find sled drags much more joint-friendly, making them the ideal alternative to things like squats, lunges, and leg presses.

How to do it:

1. Stand facing your sled with a handle in each hand. Bend your knees into a quarter-depth squat and walk backward until your arms are straight and the straps are tight.
2. Without bending your arms, walk backward while dragging the sled. Push your heels into the floor to maximize quadriceps recruitment.
3. You can also do this exercise hands-free by fixing the straps to a belt around your waist.

Wrapping Up

There is nothing inherently wrong with leg extensions. In fact, for isolating your quads, they’re tough to beat. That said, there is more than one way to overload your quadriceps, and it’s always useful to have a variety of exercises in your training toolbox so you can change exercises from time to time.

So, whether you are bored of leg extensions, find that they hurt your knees, or don’t have access to a leg extension machine, you now have 13 alternatives you can use to sculpt the quads of your dreams.

Work hard, and your friends will soon be calling you Quadzilla!

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