Are you looking to train leg extensions, but don’t have access to a machine?

Or, maybe the facility you train in just has a low-quality machine.

Whatever the case, knowing what makes a good substitute for leg extensions is knowledge worth having; because not every quadricep exercise will work.

So, the aim of this article is to provide you with 5 different alternative exercises to machine leg extensions, explain why I think they are better exercises overall, and explain why movements such as squats are not good substitutes.

If you have any questions left unanswered, you are welcome to email me at info@FitnessSimplified.org or comment below.

What makes an exercise a good alternative to leg extensions

Squats and most lunge variations do NOT make good alternatives to machine leg extensions.

I will explain why in a later section of this article to save you time.

However, the key point to know is that leg extensions involve movement ONLY around the knee joint, not the hip.

Therefore, for an exercise to be a suitable swap, it must involve movement ONLY around the knee and not the hip.

Leg Extension Alternatives

The beautiful thing about the following exercises is that they need no equipment to do, so you could even do them at home if needed.

Furthermore, I would argue these are far more effective than their machine counterparts, though I’ll save my reasoning for this for later.

The following exercises are listed in order of their relative difficulty. In other words, the first exercise is the easiest and the last exercise is the hardest.

#1: Forward Lunges

If you are using this exercise as a swap for machine leg extensions here is the most important point you need to know:

You should place most of the emphasis on your BACK leg, and NOT your front leg.

Like I said previously, for an exercise to be a suitable swap for machine leg extensions it must involve movement only around your knee.

If pay attention to the back leg, you’ll notice that it is essentially performing a leg extension; foregoing any hip involvement.

This makes a great beginner exercise because you can use your front leg to control how much weight is placed on the back leg; which is the focus of training with this exercise.

How to do them:

These can be done with or without weight.

Take a step forward, and let your back knee slowly fall to the floor.

Place most of your weight on your back leg, using your front leg only for stability.

Stop when your knee is a hair above the floor.

Stand back up toward your original position, again using your back leg mainly to drive the force.

Alternate legs and repeat for whatever number of reps os appropriate for you.

#2: Eccentric Only Reverse Nordics

This movement is the first reverse nordic variation of three that I will be providing.

The term ‘eccentric’ refers to the lengthening of a muscle, or the lowering of a weight in other words.

For instance, in a bicep curl, the portion of the rep where you lower the weight is the eccentric portion.

The portion of the rep where you curl the rep up is the concentric portion.

In general, we are stronger on the eccentric portion of a movement than we are on the concentric portion of a movement.

Reverse nordics can be an intense exercise, but only performing the eccentric portion of this movement can make them more feasible if standard reverse nordics are too intense.

How to do them:

Start out on your knees on the floor.

These can be done with your toes on the ground or the tops of your feet on the ground.

Doing so with your toes on the ground is more comfortable for many, but limits your possible range of motion.

From here, lean back while keeping your hips straight.

Go back as far as you are able, and then drop your butt to take the tension off.

Sit back up from this position and repeat for however many reps is appropriate for you.

#3: Reverse Nordics

This is the standard reverse nordic movement.

As a general rule of thumb, I recommend training the eccentric only reverse nordics until you can do 10 of them at about a ~7/10 difficulty with good range of motion.

Then, move onto this version.

How to do them

Start out on your knees on the floor.

These can be done with your toes on the ground or the tops of your feet on the ground.

Doing so with your toes on the ground is more comfortable for many, but limits your possible range of motion.

From here, lean back while keeping your hips straight.

Then, keep your hips straight and drive your feet into the floor; bringing you back to the top.

#4: Weighted Reverse Nordics

Once you can perform 10 reverse nordics at a ~7/10 difficulty, then I recommend moving onto this variation.

Furthermore, I’d recommend starting with only 5-10 pounds as the intensity of this movement can increase quickly.

How to do them

Start out on your knees on the floor.

Hold a weight against your chest, any weight that is comfortable enough to hold will work.

These can be done with your toes on the ground or the tops of your feet on the ground.

Doing so with your toes on the ground is more comfortable for many, but limits your possible range of motion.

From here, lean back while keeping your hips straight.

Then, keep your hips straight and drive your feet into the floor; bringing you back to the top.

#5: Sissy Squats

Sissy squats are the most advanced of the exercises to be shown in this article.

I recommend moving to this variation once you can perform 10 weighted reverse nordics with 20 pounds and good range of motion

How to do them

Start out by standing up, ideally holding onto something with one hand to ensure balance isn’t a problem.

Descend by leaning your torso back and sending your knees forward.

Make sure to only bend at the knees. Keep your hips straight.

Utilize as much range of motion as you are able. This means getting your knees to the floor and getting your torso as far back as possible.

Don’t force the range of motion at first if you are unable. Do what you can, and progress the range of motion over time.

Why squats and most lunges are NOT good alternatives to leg extensions

As previously mentioned, squats involve movement around the hip and knee; while leg extensions involve movement only around the knee.

This has crucial implications.

There are 4 quadricep muscles.

3 of which only cross the knee joint.

1 of which, the rectus femoris, crosses the knee AND the hip joint.

Therefore, as you descend in a squat, the rectus femoris lengthens at the side of the knee but shortens at the side of the hip.

This results in no net change in muscle length, meaning the rectus femoris is not contributing.

This has been confirmed in the research, as the rectus femoris goes relatively untrained during squats and most lunge variations [sources: 1,2,3].