Leg extensions are one of the most popular machine exercises you can do in a gym. Yes, they do target the quadricep muscles which are the primary muscles involved in the vertical jump, but this doesn’t necessarily mean we should spend much time doing leg extensions.
Despite improving quadricep size and strength, leg extensions are relatively ineffective at increasing your vertical jump mainly because of how they neglect the aspect of triple extension.
In this article we’ll dive deeper into the reasons why leg extensions are an inefficient way to train your vertical jump, what they’re actually good for, and what exercises you should mainly be focusing on.
Why Leg Extensions Won’t Help Your Vertical Jump
The primary reason leg extensions are no good for vertical jump training is because they’re an ‘isolation’ movement which requires very limited range of motion, minimal joint stabilization, and unnatural load distribution.
Lack Of Triple Extension
The vertical jump is all about ‘triple extension’ which is where your hip, knee, and ankle joints all extend in unison creating a full body explosive movement.
Naturally, when training to improve our vertical jump, we need to be focused on doing exercises which replicate this triple extension movement as closely as possible.
Unnatural Load Distribution
When doing leg extensions, there’s no eccentric load on your hips or ankles because of the seated position. As a result, you’re left with a highly unathletic movement, no activation from stabilizer muscles, and single as opposed to triple extension.
My opinion is that the best vertical jump exercises are the ones that train at least double extension (hip and knee) and some triple extension where possible.
What Leg Extensions Are Good For
Now just because leg extensions aren’t ideal for vertical jump training, doesn’t mean you should never do them. It just means if your focus is on improving your vertical jump, you should spend significantly less time on this machine.
- Leg extensions are a great way of developing your VMO (teardrop muscle on inside of your thigh) and preventing tendonitis – This is super important for vertical jump aspiring athletes because quite often this muscle is underdeveloped, particularly in younger athletes. Volleyballers, basketballers, and track athletes that suffer from patella tendonitis will often find symptoms improve when they start incorporating leg extensions into their routine to help bulletproof this knee joint.
- Develop size and strength as a finishing exercise – If you’re looking to add some more mass to your legs, you can include leg extensions after the bulk of your compound lower body movements to drive blood flow and stimulate muscle growth.
Increase Your Vertical Jump With These Exercises Instead
Two words: compound movements.
Two more words: back squat.
As I discussed earlier, the best vertical jump training exercises mimic triple extension. This means they generally look somewhat like a vertical jump in nature – note that sitting on a chair swinging your legs back and forth does not (leg extensions, essentially).
Here’s a quick list of far superior vertical jump training exercises to center your workouts around. Do the vast majority of your training volume with these exercises if you want to jump higher!
- Barbell back squat – This is the big daddy of vertical jump training. With full hip and knee extension and core/stabilization involvement, this is the sort of strength movement you want to be doing.
- Bulgarian split squat – As far as unilateral vertical jump strength movements go, the BSS is the holy grail. Read more about why the Bulgarian split squat is so effective for vertical jump training here.
- Jump squat – This one’s more of a power movement but research has shown the jump squat to be extremely effective at developing vertical jump. It should be pretty obvious why, it’s literally just a weighted jump!
- Power clean – As far as Olympic movements go, the power clean is by far the best for developing vertical jumping ability, for a multitude of reasons. Learn more about why the power clean is an excellent vertical jump exercise here!
- Glute ham raise – When we’re thinking about developing a super strong posterior chain, the single best exercise you can be doing is the GHR because of the huge force you can generate through hip extension.
- Hip thrusts – And to round things out, hip thrusts are the best way to target glutes for vertical jump training – again the focus is on hip extension here.
Do Leg Curls Help Vertical Jump?
Leg curls, just like leg extensions, are not an effective vertical jump exercise because they do not mimic triple extension in any meaningful way.
In fact, leg curls don’t train extension at all. This is knee flexion movement which trains the opposing muscle group (hamstrings) to the knee extensors (quads).
This isn’t to say you should never train knee flexion – it’s super important to make sure these opposing muscle groups are well balanced, but when it comes down to what’s going to move the needle in your vertical jump training, this ain’t it!
You can do all the leg curls you like as finishers or accessory movements, but you should never have this as a primary focus for any of your vertical jump training sessions.
What About Leg Press?
Leg press is another one I get asked about all the time. In my article ‘Does Leg Press Increase Vertical Jump‘ I explain in much greater detail why it also falls into the bucket of inefficient vertical jump training exercises.
There’s actually a good amount of science on this one, which I unpack in the above article. But essentially it boils down to the same thing: no load on the hips or ankles, and only knee flexion and extension.
It’s impossible to perform a vertical jump without load on the hip joint, but exercises like the leg press and leg extension neglect this reality.
So by now it should be pretty clear that leg extensions are not a particularly worthwhile vertical jump exercise primarily because of how poorly it replicates triple extension.
Having said that, I still do leg extensions fairly regularly at the end of my leg workouts to give my VMO some extra attention which helps stave off patella tendonitis.
So it’s perfectly fine to do occasionally, but you should never think of the leg extension as a primary exercise in any vertical jump training workout.
To make sure you’re choosing the correct exercises to maximize your vertical jump, check out my roundup of the best vertical jump programs for 2023.