Bigger Quads: This NEW Study is Epic

Summary

The video from 'House of Hypertrophy' explores the most effective exercises for maximizing quadriceps hypertrophy, focusing on two variations of leg extensions. A study compared a traditional leg extension with one where the hips are flexed to 40°, finding that the latter significantly increased rectus femoris growth. The video discusses the benefits of training muscles at longer lengths and suggests alternative exercises like reverse Nordic curls and squats for those unable to perform leaning back leg extensions. It also touches on the role of combined knee and hip extension exercises in developing vastus muscles, concluding that a mix of isolated and combined exercises is ideal for overall quad growth.

Takeaways

• 🏋️‍♂️ The study compared two variations of leg extensions to maximize quadriceps hypertrophy, emphasizing the importance of engaging all four heads of the quadriceps muscle.
• 🧬 Leg extensions are particularly effective for growing the rectus femoris, a two-joint muscle that crosses both the hip and knee joints, which is often less targeted by other exercises like squats and leg presses.
• 📊 In the study, 22 untrained men participated, and the results showed that a leg extension with a 40° hip flexion resulted in 1.4 to 2.7 times greater growth in the rectus femoris compared to the traditional leg extension with 90° hip flexion.
• 💡 The 40° hip flexion leg extension allows for a more stretched position of the rectus femoris, which is believed to contribute to increased muscle growth due to the longer muscle length.
• 🔄 The other three heads of the quadriceps (vastus lateralis, vastus medialis, and vastus intermedius), being one-joint muscles, showed similar growth between the two leg extension variations as they move through the same range of motion.
• 🤔 A Japanese study with nine bodybuilders suggested that both 0° and 40° hip flexion leg extensions could be beneficial for trained individuals, with a slight preference for the 40° variation.
• 🚫 For those unable to perform leaning back leg extensions, alternative exercises like the reverse Nordic curl and squat may be effective, as they allow for even greater knee flexion and lengthening of the quadriceps.
• 🔄 The growth of the vastus muscles from leg extensions compared to combined knee and hip extension exercises (like squats, lunges, or leg presses) appears to be similar, but with higher activity levels in the vastus muscles during the latter exercises.
• 📉 Electromyographic studies indicate that combined knee and hip extension exercises may elicit higher activity in the vastus muscles, suggesting potentially better growth in certain regions for these exercises.
• 💪 To maximize overall quad growth, incorporating both isolated knee extensions and combined knee and hip extension exercises in a workout routine is recommended.

Q & A

What is the main focus of the study discussed in the video?

The study focuses on comparing two different leg extension variations to determine which is more effective for maximizing quadriceps hypertrophy.

Why are leg extensions considered important for quad development despite other exercises like squats and leg presses?

Leg extensions are important because they have been documented to grow all four heads of the quads, especially the region that squats and leg presses minimally grow.

What were the two leg extension variations compared in the study?

The study compared a typical leg extension with the hips flexed at 90° and a variation with the hips flexed to 40°, with the knee joint moving from 110° to 0° in both cases.

How did the study control for individual differences among the subjects?

The study had each subject train with both leg extension variations, which helps control for differences in genetics, nutrition, and outside lifestyle factors.

What muscle in the quadriceps showed significant growth with the 40° Hip Flex leg extension?

The rectus femoris showed 1.4 to 2.7 times greater growth with the 40° Hip Flex leg extension.

Why does the rectus femoris benefit from the 40° Hip Flex leg extension?

The rectus femoris is a two-joint muscle that crosses both the hip and knee joints. Leaning back in the leg extension allows it to be lengthened more, which can lead to greater muscle growth.

What were the findings regarding the growth of the vastus lateralis in the study?

The growth of the vastus lateralis at both the upper and lower regions was fairly similar between the two leg extension variations.

What does the study suggest for trained individuals regarding leg extensions with different hip flexion angles?

The study suggests that trained individuals might also benefit from leaning back leg extensions, with no significant difference between 0° and 40° of hip flexion for upper and middle rectus femoris activity.

What are the alternative exercises suggested for those who cannot perform leaning back leg extensions?

The reverse Nordic curl and squat are suggested as potential alternatives to leaning back leg extensions for growing the quads.

How do combined knee and hip extension exercises compare to isolated knee extension exercises for quad development?

Combined knee and hip extension exercises are likely to grow the vastus muscles well, but they may not be as effective for growing the rectus femoris as isolated knee extensions.

What is the recommendation for maximizing overall quad growth based on the video?

To maximize overall quad growth, it is recommended to include both an isolated knee extension and a combined knee and hip extension exercise in a workout routine.

Outlines

00:00

🏋️‍♂️ Maximizing Quadriceps Hypertrophy with Leg Extensions

This paragraph discusses the effectiveness of leg extensions in maximizing quadriceps hypertrophy compared to other exercises like squats and leg presses. It highlights a study that compared two variations of leg extensions: the traditional one with the hips flexed at 90° and another with the hips flexed at 40°. The study involved 22 untrained men who trained both variations, and it was found that the 40° hip flex leg extension significantly increased the growth of the rectus femoris muscle due to its two-joint nature, which allows for a more stretched position. The vastus lateralis growth was similar between both variations. The paragraph also suggests alternative exercises like the reverse Nordic curl and squat for those unable to perform leaning back leg extensions, and it touches upon the potential benefits and limitations of these alternatives.

05:02

📊 Insights on Leg Extensions and Alternatives for Quad Growth

This section delves into the specifics of how leg extensions can be modified to enhance the growth of the quadriceps, particularly the rectus femoris. It references a Japanese study involving nine bodybuilders that suggests both 0° and 40° hip flexion leg extensions can be beneficial for trained individuals, with a slight preference for the 40° variation. The paragraph also explores the possibility of muscle growth being influenced by muscle lengthening and the potential for exercises like the reverse Nordic curl and squat to offer even greater lengthening and growth. It discusses the limitations of electromyographic studies and presents findings from a study comparing leg extensions to Smith machine squats, indicating that while leg extensions are superior for rectus femoris growth, squats may be more effective for vastus lateralis. The paragraph concludes by emphasizing the importance of combining isolated knee extensions with combined knee and hip extension exercises for optimal quad development.

10:03

🔗 Conclusion and Resource Recommendation for Muscle Building

The final paragraph summarizes the key points discussed in the video and provides a resource recommendation. It emphasizes the importance of both isolated and combined knee and hip extension exercises for maximizing quad growth. The paragraph also introduces the alpha progression app, a tool designed to help users generate evidence-based muscle-building programs tailored to their individual needs. The app offers a vast exercise database, personalized workout plans, and performance analysis to assist users in their muscle-building journey. The video concludes by encouraging viewers to explore the alpha progression app and other resources for further information on muscle hypertrophy.

Keywords

💡Hypertrophy

Hypertrophy refers to the increase in muscle size, which is the primary focus of the video. The script discusses various exercises and their effectiveness in promoting muscle growth, particularly for the quadriceps. It is central to the theme as the video aims to provide insights into maximizing muscle growth, specifically for the quads.

💡Quadriceps

The quadriceps, often referred to as 'quads', are a group of four muscles at the front of the thigh responsible for knee extension. The script emphasizes the importance of training all four heads of the quadriceps to achieve balanced muscle development. The exercises mentioned in the video are aimed at hypertrophy of these muscles.

💡Leg Extensions

Leg extensions are a type of resistance exercise that targets the quadriceps. The video script compares two variations of leg extensions, one with a typical hip angle and another with a modified hip flexion angle, to determine which is more effective for quad hypertrophy. The findings suggest that leg extensions, especially the modified version, can significantly contribute to the growth of the quadriceps.

💡Hip Flexion

Hip flexion is the movement of the thigh towards the abdomen, which is a key factor in the modified leg extension exercise discussed in the script. The video highlights how changing the angle of hip flexion from 90° to 40° during leg extensions can enhance the stretch on the rectus femoris, a two-joint muscle, potentially leading to greater muscle growth.

💡Two-Joint Muscle

A two-joint muscle, like the rectus femoris, spans across two joints and is involved in the movement of both. The script explains that because the rectus femoris contributes to both knee extension and hip flexion, modifying the leg extension to include more hip flexion can place the muscle at a longer length, which may stimulate greater hypertrophy.

💡Rectus Femoris

The rectus femoris is one of the four heads of the quadriceps and is specifically highlighted in the video for its potential for greater growth with certain exercises. The script details how the modified leg extension with 40° hip flexion can lead to increased growth of the rectus femoris due to its two-joint muscle nature.

💡Vastus Lateralis

The vastus lateralis is one of the four heads of the quadriceps and is mentioned in the script as being affected by both leg extension variations. While the growth of the rectus femoris was significantly greater with the modified leg extension, the vastus lateralis showed similar growth between the two variations, indicating its response to standard knee extension exercises.

💡Rep Range

The rep range refers to the number of repetitions performed in a set of an exercise. In the script, it is mentioned that once subjects reached 20 reps in the first set, the load was increased to maintain a rep range of 15 to 20. This approach is used to ensure progressive overload, a key principle for muscle hypertrophy.

💡Untrained Subjects

The script refers to a study involving untrained men to examine the effects of different leg extension variations on muscle growth. This is important as it provides insight into how beginners might respond to these exercises, which can be useful for individuals new to strength training.

💡Alternative Exercises

The video script suggests alternative exercises such as the reverse Nordic curl and squat as potential options for those who cannot perform the modified leg extensions. These alternatives are highlighted as they also involve minimal hip flexion and allow for greater knee flexion, which may contribute to further muscle lengthening and growth.

💡Combined Knee and Hip Extension Exercises

The script discusses the effectiveness of exercises that involve both knee and hip extension, such as squats and lunges, in developing the quadriceps. While these exercises may not grow the rectus femoris as effectively, they are shown to develop the vastus muscles well, suggesting a combination of exercises for overall quad development.

Highlights

A new study compares two variations of leg extensions for maximizing quadriceps hypertrophy.

Leg extensions are effective for growing all four heads of the quads, especially the region minimally affected by squats and leg presses.

The study recruited 22 untrained men to compare the typical leg extension with hips flexed at 90° and a variation with hips flexed to 40°.

The 40° Hip Flex leg extension showed 1.4 to 2.7 times greater growth in the rectus femoris.

Rectus femoris, a two-joint muscle, benefits from the leg extension leaning back due to its involvement in hip flexion.

Training muscles at a longer length, as achieved with the 40° variation, seems to promote more muscle growth.

The other three quad heads, being one-joint muscles, are expected to grow similarly between both leg extension variations.

A Japanese study suggests that both 0° and 40° hip flexion leg extensions may benefit trained individuals.

The study indicates no significant difference in muscle activation between 0° and 40° hip flexion, favoring the 40° variation.

Alternative exercises like reverse Nordic curl and squat could be effective for those unable to perform leaning back leg extensions.

These alternatives allow for greater knee flexion, potentially benefiting the growth of the rectus femoris and other quad heads.

There may be a threshold to muscle lengthening's benefit for growth, which needs further research.

Normal leg extensions are still valuable for muscle building, even if not the most efficient.

Combined knee and hip extension exercises are suggested to develop the vastus muscles well, despite minimal rectus femoris growth.

Electromyographic analyses indicate higher activity of vastus muscles during squats, lunges, or leg presses compared to leg extensions.

A study found that leg presses grew the vastus lateralis better than leg extensions.

For overall quad growth, incorporating both isolated knee extension and combined knee and hip extension exercises is recommended.

The Alpha Progression app is highlighted as a tool for generating evidence-based, personalized muscle-building programs.

Transcripts

welcome to the house of hypertrophy what

are the most effective and efficient

exercises to maximize quadriceps

hypertrophy the findings of a brand new

study have some potentially important

details it has compared two different

leg extension variations some of you may

be thinking why leg extensions aren't

squats and leg press variations the best

way to grow the quads as we'll see later

these exercises absolutely can grow the

quads well but they aren't enough

because they fail to meaningfully grow a

certain head of the Quad leg extensions

on the other hand have been documented

to grow all four heads of the quads well

especially the region that squats and

leg presses minimally grow we'll also

mention some underappreciated

alternative two leg extensions if you

can't train

[Music]

them 22 untrained men were recruited

with one leg subjects trained the

typical leg extension the hips were

flexed at 90° and they moved the knee

joint from one 110 to 0° with the other

leg they train the leg extension with a

Hip Flex to 40° with a knee joint also

moving from 110 to 0° so the only

difference was this variation has us

leaning back the subjects trained both

exercises with these variables whenever

subjects reach 20 reps on the first set

load was increased to keep them in the

15 to 20 rep range the fact each subject

trained with both exercises was great

since this means the same subjects were

in both conditions therefore differences

in genetics nutrition and outside

lifestyle factors likely won't confound

the study the quadriceps consist of four

heads and the researchers measured both

rectus femoris and vastus lateralis

growth each at an upper and lower region

the result rectus fous growth at both

regions was 1.4 to 2.7 times greater

with a 40° Hip Flex leg extension how on

Earth is this possible the rectus

femoris is what we call two-joint muscle

it crosses both the hip and knee joints

so besides contributing to knee

extension it also contributes to hip

flexion consequently with a leg

extension leaning back allows us to

lengthen the rectus femoris more that is

it's in a relatively more stretched

position this is important as mentioned

previously at the house of hypertrophy

training muscles at longer length seems

to build more muscle and this new study

adds to this body of literature with a

rectus growing better with a leg

extension variation that positions it at

a longer

length the other three quad heads are

one joint since they just cross the knee

so all contribute to just knee extension

so provided we're moving the knee joint

through the same range of motion which

was done in this study we'd expect these

muscles to grow similarly between both

variations as they're moving through the

same muscle lengths indeed vastest

lateralis growth at both regions was

fairly similar between the two leg

extension variations

there are at least three questions you

might have the subjects were previously

untrained what about trained people what

about laying down to 0 de of hip flexion

and what about alternatives to leaning

back leg extensions a paper from Japan

published last year potentially answers

the first two questions nine

bodybuilders were recruited they

performed the leg extension with 0 40

and 80° of hip flexion during each

muscle activation was indirectly

measured with MRI both the zero and 40°

hip flexion leg extensions produced

higher upper and middle rectosis

activity than the 80° variation lower

rectos morus activity did not

statistically differ between them but we

still see the values tended to be higher

with a z and 40 degree variations

therefore this study suggests trained

individuals might also benefit from

leaning back leg extensions but there

doesn't seem to be a greater benefit for

0° compared to 40° of hip flexion if

anything the raw numbers favor the 40°

variation however I will note that

although this muscle activation

measurement has been associated with

actual muscle growth in previous

analyses the context of these papers are

important none of these papers verified

that this muscle activation measurement

successfully predicted muscle growth

when comparing exercises at different

muscle lengths and I think it's possible

this measurement fails to fully account

for Passive forces that occur when a

muscle is at longer lengths I say this

to say it's possible these results

underestimate the muscle growth

potential of 0 degree hip flexion leg

extensions thus hopefully we get

research comparing the 0 to 40°

variations for now we can at least say

it's likely both zero and 40° hip

flexion leg extensions are better than a

traditional variation for overall rectus

sorous development but what if you can't

perform leaning back leg extensions the

reverse Nordic curl and squat are

both potentially great Alternatives both

are performed with virtually no hip

flexion just like the0 degree hip

flexion leg extension but unlike the Z

degree hip flexion leg extension both of

the exercises allow us to bend our knees

to an even greater degree of flexion so

in addition to lengthening the rectus

furus even more all other three quad

heads are going to be trained at even

longer muscle lengths than what we

achieve with leg extensions does this

mean these two exercises can grow these

three quad head even more than any leg

extension variation maybe but it is also

possible that there's a threshold to the

amount of muscle lengthening that's

beneficial for growth such that these

two exercises don't build the three quad

heads more than any leg extension

variation there are also some other

subtle differences between these

exercises hopefully future research

Compares them to tease out any potential

differences in growth for now at least I

believe we can hypothesize both of these

are going to be excellent alternatives

for growing the quads particularly the

rectus femoris depending on your current

level these two exercises may be too

hard or easy to perform but I've

mentioned some training and progression

tips in the pinned comment if you're

interested this discussion so far has

been centered around maximizing muscle

hypertrophy but I will say if you just

rather train with normal leg extensions

that is perfectly fine at the end of the

day although it may not be the biggest

bang for your buck it still will build

mus

[Music]

musle the exercises mentioned so far

largely involved to isolated knee

extension but the quads are commonly

trained with combined knee and hip

extension exercises we have multiple

studies suggesting all of these

exercises likely minimally grow the

rectus phorus but develop the other

vastest muscles well the lack of rectos

moros growth from these exercises can

likely be explained by the simple fact

that rectos morus is a joint muscle

during the bottom position of any

combined knee and hip extension exercise

we need to produce both knee extension

and hip extension but since the rectus

sorus is involved in hip flexion the

opposite of hip extension a strong

contraction would fight against us

trying to get up the other vastus

muscles are just involved in the

extension so are free to highly

contribute to the extension in these

exercises so it makes sense these grow

well from these

exercises some of you may be Be

Wondering the leg extension also still

grows the vastest muscles how does this

growth compare to that achieved from

combined knee and hip extension

exercises most of the electromyographic

analyses I found comparing leg

extensions to squats lunges or leg

presses showed that the latter exercises

elicited higher activity of the various

vastus muscles now as mentioned at the

house of hypertree previously

electromyographic Studies have

limitations but as described by

researcher Brad shanfeld there seems to

be an upcoming study finding When

comparing leg extensions to leg presses

leg presses grew the vastest lateralis

better and that the leg extension Target

direct as for moris which is the mid mid

quad muscle MUSC that goes down the

center of the quad and the vast

lateralis one of those three vast

muscles ler on the lateral aspect of the

Quad was targeted to a greater extent

with the leg press some degree of upper

to lower Regional differences could

exist this study compared Smith machine

squat to leg extension training in

trained subjects unsurprisingly the leg

extensions grew the rectus foror as more

especially at the lower region as a note

based on the data we've seen we can

hypothesize if leaning back leg

extensions were performed much better

upper and middle rectus morus growth

would have been seen vastest lateral

growth at the upper and middle portions

tended to be better with the Smith

machine squats while growth at the lower

portion fascinatingly favored the leg

extensions I should note there were a

couple of limitations with this study so

I would like to see another study like

this but in total the available evidence

leans towards the idea that growth of

the vestus muscles at least in certain

regions can be better with combined knee

and hip extension exercises so to

maximize overall quad growth having both

an isolated knee extension and combined

knee and hip extension exercise is

probably a great idea we'll have future

videos at the house of H pery exploring

and comparing different squat leg press

and lunge variations so stay tuned for

that considering the conflicting

information across the web things can

get pretty confusing about how you may

want to train I hope the videos at the

house of I pery go some way to clearing

up this confusion but our highquality

partner the alpha progression app may

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the end of the video here's the summary

points feel free to check out the alpha

progression app or our recent deep dive

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