The Most IMPORTANT Muscle Building Stimulus (87 Studies) 

Hey all! FREE Ultimate Guide to Bench Pressing for Strength & Hypertrophy: www.houseofhypertrophy.com/free-e-book/ Read more for timestamps + link to references Timestamps: 0:00 Intro 0:35 ancient accounts of lifting weights 1:26 next year at the House of Hypertrophy 1:59 PART I: Does Mechanical Tension Stimulate Hypertrophy? 2:29 history of mechanical tension research 4:35 more recent research on mechanical tension 6:40 indirect data from human studies 7:08 PART II: Does Metabolic Stress Stimulate Hypertrophy? 7:35 metabolic stress is related to the burn and pump 7:57 concentric vs eccentric contractions 8:27 continuous isometric vs intermittent isometric contractions 8:50 limitations with classic research 9:14 the science of blood flow restriction training 11:15 blood flow restriction training produces more slow-twitch fiber growth? 13:21 metabolic stress, fiber recruitment, anabolic hormones, myokines, & the pump 15:22 metabolic stress with running and cycling 15:34 recent fascinating studies on metabolic stress 16:45 PART III: Does Muscle Damage Stimulate Hypertrophy? 16:59 The relationship between damage and soreness 17:30 microtears cause muscle growth? 17:55 is eccentric training superior for muscle growth? 18:56 muscle damage & inflammation, satellite cells, igf-1, and fiber swelling 22:02 recent fascinating studies on muscle damage 23:57 excessive muscle damage can cause muscle loss 24:40 more damage with higher reps and shorter rest between sets 25:05 effect of antioxidants (vitamin c and e) on damage, soreness, and hypertrophy 26:32 PART IV: A Deep Dive into Mechanical Tension 27:38 how much fibers produce force, and what mechanosensors detect it 29:05 one-rep max training does not build much muscle 30:52 final overview of mechanical tension 31:19 PART V: What Mechanical Tension Means for Your Training 31:46: muscle fibers and henneman's size principle 32:39 heavy load vs light load mechanical tension 33:33 training to or close to failure 33:41 very light loads and very heavy loads aren't great for hypertrophy 34:14 training muscles at stretched lengths is great for hypertrophy 34:59 why static stretching may not be great for hypertrophy 36:24 PART VI: Hypertrophy Models 37:38 does hypoxia play a role in hypertrophy? 38:14 PART VII: Summary References can be located here: www.houseofhypertrophy.com/references/

- Hi rep (better due to fact its less risky, easier to use proper technique) - Mid/low tempo - Training close/above failure - Iso hold may be also great addition, as last rep finisher - Stretched position There is a reason why ring gymnast have such a crazy physique, they checked all of this boxes... except rep ranges, but as u said, it doesnt really matter as long as proper tut is applied.

This channel is pure gold. Never ever stop making these videos, they are so helpful you can´t imagine how much. I have watched every single video like a marathon. Keep it up!

This channel has 101,000 subscribers and is 99% underappreciated and underrated. Every video is slammed full of good information. Thank you my dude, we are not worthy!

🎯 Key Takeaways for quick navigation: 00:00 📚 This video explores the scientific research on muscle hypertrophy and various stimuli. 02:26 💪 Tension generated by muscle fibers, whether active or passive, appears to stimulate muscle hypertrophy. 05:15 🔄 Total tension, regardless of being active or passive, is a powerful stimulator of muscle hypertrophy. 09:44 🩸 Blood Flow Restriction Training with light loads can be effective for muscle hypertrophy through mechanical tension. 12:45 🤔 Preferential slow-twitch fiber growth with Blood Flow Restriction Training might be due to other factors, not just metabolic stress. 16:42 💥 Evidence suggests metabolic stress is not a potent driver of muscle growth. 20:26 🤕 Muscle damage may increase Satellite Cell Activation, potentially aiding muscle growth, but its role is still debated. 23:26 🚧 Muscle damage's role in muscle hypertrophy remains uncertain, as other factors may contribute more significantly. 23:40 💪 Mechanical tension is likely the primary stimulus for muscle hypertrophy, with no strong evidence supporting metabolic stress or muscle damage as powerful drivers. 27:12 💥 Muscle fibers generate tension, detected by mechanosensors, which trigger signaling pathways for muscle growth. 32:45 🏋️‍♂️ Both light and heavy loads can stimulate muscle hypertrophy when taken to near failure, ensuring sustained mechanical tension. 35:06 🏋️‍♂️ Training muscles in stretched positions, involving active and passive forces, may enhance hypertrophy by stimulating mechanosensors effectively. 36:35 ❓ Mechanical tension might be the primary and sole stimulus for hypertrophy, with metabolic stress and muscle damage potentially acting as byproducts or playing minor roles. Future research is needed for further clarity. Made with HARPA AI

I have no idea how long this video took you to put together, but I am here to watch it, like it, commend and share it so it can spread to more people. Thank you for the great content again!

As someone who’s been lifting for 26 years, I can say with confidence that anyone watching this video can massively shortcut their hypertrophy learning journey. Your information is accurate and excellent. You’ve explained all of the key concepts with exceptional clarity, and your videos always give me food for thought, as I continually evolve my own training.

This is, in no uncertain terms, the best educational and comprehensive channel on the topic of muscle growth and you have it down to a Science. It’s so well articulated and easy to digest. I’m so glad to have found this channel and I’m so grateful to be alive at a time where I have the privilege of seeing this. This man. This channel. Must be protected at all cost.

Unreal that you're giving out such detailed quality information for free. Genuinely appreicate the effort you put into all your videos, both in terms of research and the simple easy to understand graphics. Hopefully your channel gets the recognition is so rightly deserves soon! Thanks again my man.

That's gotta be one of the best youtube channels out there, the amount of quality and work you put in these videos are really something great. I don't know how i could praise this more so congratulations and keep it up 👏

I love that when you question a study’s results, you provide links to research/vids explaining your reasoning, or otherwise just point out you are speculating when there isnt research to back it up.

Thank you for everything you do! you've truly helped me understand muscle growth as a whole and it dramatically impacted my training never stop what you do!

Im very happy to have found someone that explains everything in great detail and backed up by valid studies. There is so much mixed and false information out there that makes if very difficult to find out how to properly work out. Your channel is providing exactly what we all need and we should all appreciate your work and effort. So thanks for making all our lives easier and better!

A truly massive effort on this one, thank you so much. I have recently experienced exactly what you described with gains vs. muscle damage. I trained last year, then took 6 months off and came back. Lots of DOMS when I got back into it, and only after the DOMS went away was I able to increase the weight in my lifts and get gains. It came back quick, in 2 months I'm where I was after 5 months last year. Now my gains have slowed down significantly, but they're still there. Muscle memory is real.

This channel really helped me open my mind to different approaches to hypertrophy. I would've thought this channel would have a million subscribers! Totally underrated channel - can't wait to see this channel blow up!! Thanks for all the hard work!!

I want to thank you for several reasons for one of your master pieces so far. However, the level of details and still being able to break down complex topics were already appreciated in some comments. During the course of the video I found myself a few times wondering about something while you explained/presented a matter and right after you addressed these questions. Thank you looking at topics critically and from different angles. Yet, there were a cases where I wished for slower speed in presenting some complex matter to be even more educational. Last but not least, I want to thank you for being brave to release such a long video like this where there seems to be a trend to make contents shorter. I don't believe that humanity lost its ability to focus more than 30 seconds.

I noticed the (completely understandable) lack of uploads lately, so happy to see this video in my feed (and it's 40 minutes long LETS GOOOO). Such good content always Wishing you a warm winter and all the best for 2023!

Whoa!!! Dude!!! This channel has grown so so much and I literally couldn’t be more glad. The content is so ridiculously high quality it’s fantastic. Been with you since like 8k, so impressive to see how you’ve grown

I'm sure you've heard it a bajillion times at this point but great vid, Dhimant. This one, IMO, should be mandatory viewing for both beginners and long time lifters who want to learn the science behind a lot of the things we do in training. And of course make better training decisions relative to their individual goals in light of the knowledge gained from watching the videos. Wow. Definitely one of the most educational vids in the YT fitness community.

This video is exceptionally insightful and well delivered, as are many others on this channel. One may disagree with the studies' choice, or the conclusions, but the effort that goes into making these clips is evident and should be rewarded. I enjoy the author's comments and gathering of articles as much as I did reading MASS. Please, keep it up!

I see HoH, I click....that simple. Also, I've been a personal trainer for 13 years and this channel is SPOT ON. I'm always learning something new. Thanks a ton for what yall do. 🙏🏽

I have been training in gym, mostly with free weights, for 7 weeks now, 5 days a week. Basically, I'm using the free gym at my workplace, which only makes sense after all, because I have to come to work anyway, so why not train too while at it. Finding this channel has been a real gold mine of information for me. Already, I have made some significant progress by using the newly gained knowledge from this channel in my free weight training. Of course, I do seem to have a natural genetic inclination towards high volume training, because resting over weekend seems to be all that I need for a full recovery after 5 consecutive gym days, even if I still consider myself just a beginner. And, constantly aiming to train smarter than before to make the most out of my time in the gym has indeed been a big game changer for me, even with such a short training history. I can see the progress clearly, because I always track everything that I do in the gym with a pen and a memo in my hand. I'm the "nerdy gym bro", in other words. :)

As a guy who has been training on and off for over 40 years this presentation is excellent. Very informative. I find a combination of positives negatives slower movements and static holds work well for me.

Another amazing wrap up of current hypertrophy research. The best on RU-vid. Thank you for your hard work, we appreciate it.

Very informative and helpful video! Brings up studies helping understand the science behind the muscle hypertrophy. All people that concern about fitness should be aware of these. Keep up the good work, guys!

I know you've been doing a lot better in recent months with subscriber count. You are so close to absolutely blowing up, it's not even funny. Thank you so much for this content. Don't change too much when you become famous.

The best information channel out there! Really like the way it is created to actually review all the available research and find out the best way to build muscle. Compare to other biased channels that are more ego/opinion based on individual experience. Great job!

It is incredible the amount of effort you're putting into this channel ,hope the best for you ,easily the best sciencebased training source on this platform, keep it up!

That's the best hypertrophy vid I've ever watched, you deserve so much credit, congrats on 100k too, very deserved.

I've been trainig for 4 years and can confidently say that I'm the sea of gym content, yours are by far the best and most educational!

This channel is a goldmine for smart fitness inclined people!! Thanks for the video!

What you do needs serious skill and courage, I admire your videos and the effort it takes to create them 🔥🙏🏼

I love your content, and the sheer number of research papers you go through 🔥 I wish you could do a video on the most optimal program, or to reveal your program ❤️

As always, thanks for the work. I love the depth of detail. I am no scholar but I can follow a fair bit of this and your narrations add a sense of urgency that I need to stay focused. God bless you!

This is one of the best videos on RU-vid! I’m going to share this with all my colleagues. It’s very refreshing to see some objective data, instead of fitfluencers spewing BS on TikTok.

Gonna link your channel to every friend i have, you deserve it. Keep up the good work and smile knowing that you will achieve something great in the future

the quality of this channel is when regards to theory and study is unmatched

I'm so glad I found your channel. Keep up the incredible work mate. 11/10.

Gold worth video right here!! Thanks for putting so much effort into bringing these masterworks out!

1:35 definitely don’t forget to add the neck :) Super underrated, and makes a massive difference in the overall look of your physique, hope you consider!

Gonna check it right now - your videos are amazing!

One of the most comprehensive videos on muscle growth on the internet, good job.

Just commenting so that RU-vid recommend this channel to much people as possible. I'll watch it after finishing my exams.

there are just a lot of things we learn from you bro,this is almost like an infallible conclusion-making pope's magisterium but for fitness,Thanks!

Your channel is awesome! I can't even tell you how much it's helping me. Thanks a lot!

I've watched many of your videos and this helped to put so much more together! Thank you !!!! Bro make more like this!

This channel is a gem. Hats off to the work you have put to make this wonderful video. You diserve way more than a million subs, I hope you reach that slab soon. ❤

I can't even express how I have enjoyed this video, great job!

you are something else dude. Thank you so much for your dedication and profesionalism

Amazing video. It's good to know all that valid information and not misinforn other people when giving them advice and not utilise useless practices by myself also. Wanna say that I really appreciate work you doing to make this information accessible for perseption in short (compare to reading, founding, understanding all that information by itself) video.

This is like next level top tier more information than any other fitness content creator ever.

it is insane we can watch this for free, thanks a lot, mate.

Awesome info man! 👏🏼 Keep up the great work! 💪🏼

This channel needs more attention. Amazing information

First time I watched a video on your channel. One word mate... FANTASTIC!!!

this video was beyond amazing. Probably one of the best fitness videos I've ever watched.

I was thinking of watching as many videos of you as possible and put together the conclusions myself, then you created this video. In a world where even the simplest things cost money, learning all of these for free is unbelievable. I hope you don't get to a point where you decide to restrict your content to paid subscribers or something like that in the future. Also congratz on reaching 100K. Waiting for new year's ultimate guide videos.

6 months of exercise physiology comprised into 40 mins. Great job!

Great video as always!! I think it would be great if you could do a summary video of all your findings as I sometimes get confused with the new/old video/studies you talk about! I would love that! Anyways good job!

Gold video as always! Very informative and clear to the point

the amount of valuable info here is unreal

i just discovered this channel recently and have been watching a lot of it. i think my favorite thing is how often you upload. there are other good science-based fitness channels (like jeff nippard's), but he uploads so rarely in comparison.

Every video is amazing. I hope you blow up and get the recognition you deserve.

DUDE, i'm so happy I came across your page. Thanks for providing so much value, sending a internet hug your way LOL.

This is a masterpiece. Very well done.

So Mike Mentzer was right. You activate as much as possible muscle fibers for decent duration with 6-10 rep range. Since it is hard to predict how many reps you are away from failure, going to failure will guarantee the stimulation. You achieve both active and passive tension by controlling and emphasizing negative of the excersices. In addition since the mechanical tension is the primary key there is no need to put more muscle damage by doing more than 1 set (after you stimulate the growth). More muscle damage will cause to more resources will be used for healing instead of growth, so it actually has negative effect for growth. He is absolute genius. Thank you for your effort to explain all the concepts as clearly and simple as possible.

Great presentation. One thing that is missing here in my opinion is the active increase in nutrient delivery during and after the swelling. The main reason why a tissue creates inflammatory response is to get more nutrients and more blood flow to get rid of the metabolites and reconstruct as soon as possible. To increase the size of the muscle tissue, one needs more nutrients than before, like any other system that wants to expand. Therefore, I assume that an increased blood flow might be a direct source for growth. Also each and every fast twitch fibre needs glycogen and glycogen binds to water. To have enough glycogen, you need to accept 3x the amount of water around the fibre. This sarcoplasmic growth is necessary for fast twitch athletes to perform. The soreness and swelling helps with gathering both the glycogen and water (also hyaluronic acid to bind all) in a shorter time period. On the other hand, slow but steady growth without inflammation is also possible and well observed, especially in younger athletes. This might suggest that hormonal impact is greater than inflammatory impact on muscle growth. I stop with my ramblings now. Thanks for the great video!

One of the best videos ever made

Excellent video. Thanks!

You are a legend my friend, a god-sent gift to all us! 💪 Merry Xmas to everyone🎄

Thanks for the effort in making this and future videos!

This channel is bloody pure gold!! You have one of the most comprehensive + scientific + unbiased YT channels on strength/hypertrophy training!! I don't know who you are, and you've earlier alluded that you wish to remain anonymous, but, you're doing an absolutely fantastic job on summarizing the scientific literature!! BTW, would you be interested in doing similar deep dives in the cardio litt. -- for both cardiovascular/cardiopulmonary end points + fat loss? LISS, MISS, HIIT, MICT etc etc etc...? I think people would be interested in that, and I'd also like to know your views on this...

Great work as always 👏🏻

So needed tons of studies, to proof exercise grow your muscles. Wow.

Thank you for the research done!

Great Video and respect for putting together a first class video, extremely enlightening thanks for posting

Incredible video as always, thankyou!

great work bro, grats on 100k

Congrats on 100k one of the best fitness channels

Thanks for all the quality content and references. Your content has really helped me wade through all the clickbait BS on youtube.

Love the knowledge!!!🎉

Boy, what an iNSANE video! Thanks!

Amazing video. Thank you for your time and dedication

Great video! A lot of valuable information and studies!

Very interesting video, good work mate!

Good things come to those who wait. Another good one thanks.

Thank you for the great content and I look forward to future videos. Also I would say it is possible to use biomechanics in your training, for example in the incline dumbbell curl, the dumbbell exerts very little force on your biceps at the bottom of the movement, whereas if you use cable then you will get a better stretch.

yo 100k already? Deserved! Congrats!

Thank You

Literally the best hypertrophy channel on youtube!

My summary of the entire video : 1. Low rep high weight & high rep low weight are not ideal. Ideal is lifting a high enough weight for the longest time possible to grow muscle. What grows muscle is keeping them under the most tension for the longest time. Too high weight & the time is too low, too low weight & you’re basically doing cardio & not building much muscle. There is a sweet spot of progressive loading where you challenge your muscle to grow. 2. Concentric exercise does not take advantage of isometric (holding in place) and eccentric (negative release) movement, which also build muscle. It seems the ideal is to shorten the muscle, pause, slowly release, pause, shorten & repeat. Slowly controlling the entire movement of the muscle in both directions will stimulate it the most. Not doing eccentric for the slow release of weights, you’re missing out on keeping it under longer tension. So when you release/drop weights quickly, it is waisted time & nothing is gained. It is also important to do the full range of the muscle, as a stretched out muscle under resistance is also very good. People often say “farmers strength” or look at gymnasts, they are very strong for their size. It seems by what they do, it forces all movements, concentric, isometric and eccentric. Especially isometric as they often hold a weight in a given position. 3. Combining 1&2 & according to this video, it seems people who ego lift with too high weight actually grow less muscle & overall strength, as they tend to throw the weight around because it is heavy, so they only PARTIALLY build muscle on the concentric movement. If you work with more manageable weight and control the weight out as you release + pausing on either side, you’re maximizing the muscle load & thus muscle growth. It might also grow different parts of muscles better, aka the muscle fills out in a better shape. Also, not using overly high weights for your strength is safer from injury. 4. Work out near to or to failure to maximize muscle tension & growth. 5. Supersetting seems to be a very good strategy for best results for the time exercised, working opposite muscles (like an exercise that utilizes biceps & triceps, or upper vs lower body). So while one muscle rests, you are putting the other in tension. With this approach, you can almost none stop be putting one muscle under tension at all times. Why just sit around to rest, do a different muscle & the other one will rest during this set. There is an art to this as exercises like bench and triceps aren’t good in supersets because they both utilize the tricep to push. I sometimes do Quad-sets (combining 4 exercises), today I did biceps, squats, triceps & traps. Not much muscle overlap so I was able to do these non stop for 20 minutes (3 sets each), with a few seconds rest between as I moved to the next exercise. This maximized my tension & muscle building, as normally more than 70% is spent resting, mine was like 10-20%. I do these more when I want a full body workout or I’ve been out of the gym for a while (way to awaken all the muscles before focusing on any). 6. This is from my experience, higher reps and lower weight seems to be better for muscle definition (muscle striation/threading) vs higher weights are better for size & overall muscle contours. 7. Again my experience, try to combine exercises and motions, to replicate natural movement out of necessity, vs working a single muscle. Farmers and gymnasts are very strong for their size because they do complex motions, utilizing multiple muscles at once. This is also much more efficient, why just do an overhead press, pick it up from the ground & hit the back, & biceps also. They also hold positions/weight & have to control weight when they release. You teach your body muscle connection and syncing. This will also build a more natural physique better suited to live life. How many dudes do you see walking around with their arms buffed out because all they do is pump their chest, shoulders & biceps/triceps? But then they become so stiff & lack motion, they can’t even throw a proper punch. So many people have muscle imbalances & in turn these muscles warp the skeletal structure. I’ve seen guys pump their chest so hard that their shoulders cave forward & the back rounds like crazy, the chest is pulling too hard inside, & the upper back muscles are too weak to counterbalance. You want balanced muscles so the tension is equal on both sides, biceps/triceps, chest/back, front/rear neck, quads/hamstrings, glutes/hip flexors. Often people work out what they see in the mirror and skip back, creating problems. The best example I can give of why this is important is lower back pain, this usually occurs from office/computer jobs & sitting lifestyle. Why? Imbalance between the hip flexor and glutes, the hip flexors are over tight because half their life is spent in a sitting position (forward bend, basically hip flexor is under tension 10 times longer than glutes in any given day) and the glutes are too weak because they are stretched & weak from sitting on them. A tell tale sign is a really flat butt & no lower spine curve, glutes are dead & Mia. This imbalance creates a pull on the spine from the hip flexor and people have chronic back pain. Cure is to strengthen glutes & stretch the hip flexor. Don’t workout for ego, do it for balance & ability, for health. Everybody wants to be that big scary guy at the gym, for me they’re a joke. He can barely move & slow like a sloth, unable to generate momentum & I can strike him 3 times before he even winds-up his first. There is a HUGE disconnect how some people look and how dangerous they are, be most afraid of the quieter, more humble reserved & less flashy guy not willing to talk shit. People talk shit because they know all they have is intimidating and don’t have much left when it hits the fan. Train MMA & protect the weaker, the bigger ACTUAL killer you become, the less likely you want to solve it in that matter. Notice most that can kill, will bow out & seek peace, & most who don’t know how to fight, pound their chest & run their mouths. One knows what he is capable of & it scares him, the other has to prove something because he”s actually weak & a fraud. Don’t be fake, don’t take the easy way out & put in the work. Respect yourself.

Waited for this one 👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼

87 studies⁉ What a treat👍

I would love to see a deeper dive into Junk Sets and/or how many sets per muscle group per week is optimal.

This looks to be very valuable info. Thank you!!!

What a golden channel.

The study by J. Schott et al. that you mentioned about isometric exercise has a good design. Total volume and intensity are equal, but under different metabolic stress. That's what one needs to compare, not other studies that you refer to. Repetitions with long rest between reps but high intensity for 90% of RM for one group and metabolic set 50%-70% of RM with equal total volume are required.

Key points I took away from this video along with dots I've connected and questions that came up: 1. Fast twitch muscle fibers have the most potential for muscle growth which is why you would want to lift heavy. 2. Muscle fibers have sensors that detect tension which seems to be where hypertrophy process is signaled from. 3. Time under tension within a certain time window also seem to be an important factor because otherwise we would just introduce one heavy weight rep and trigger hypertrophy, which doesn't happen. Due to this reason we don't want to train with the one rep max weight if our goal is hypertrophy. 4. Since there's such thing as regional hypertrophy for different parts of the same muscle group, and also because active and passive tensions are both important for hypertrophy, it would be a good idea to perform exercises with a full range of motion and without neglecting the eccentric portion of an exercise. Here's an interesting food for thought: Let's say 40 pounds is my one rep max weight for a bicep curl. It should recruit almost every muscle fiber I have in my bicep. And let's say I can do 8 reps with 30 pounds. That will recruit less fibers but if I perform 3 sets of 8 reps where each set is very close to failure, I will gain mass on the bicep. As we decrease the weight it would be a safe assumption to say that we'll recruit less fibers. At the same time, I know that doing 3 sets of 30 reps with an appropriate weight can also trigger hypertrophy. Then should we see a significant difference in the mass gained by the 3 sets of 8 reps versus 3 sets of 30 reps? Because the amount of fast twitch fibers recruited for 8 reps weight would be greater than 30 reps weight. 30 reps would have higher tension duration on the slower twitch fibers. An important question I can't seem to get an answer for: Why do we need to do 3+ sets of an exercise when we can reach close to failure in one set? This whole concept of mechanical tension is very vague so far. I have no real understanding of how much time under tension would be needed for hypertrophy. Under this concept the idea would be that 3 sets will give you sufficient time under tension to trigger hypertrophy? What about 1 set? what about 10 sets? That's for one exercise. Many people believe you must do 2 or 3 or more exercises for one group of muscle in one day and they would be doing 3 sets of each exercise minimum. My question is, why can't we do one set of one exercise to failure or close to failure and have just as much hypertrophy? If there's capacity for more hypertrophy by introducing more time under tension, where's the limit and how do we find out where our individual muscle limit is?

This is awesome work and I dont know when I found this channel but it was a while ago and now I seen its gotten much larger, congrats! Much deserved. My head was spinning towards the end, maybe shouldnt have listened at 2x speed, lol.. Can you in simple terms say what the research means in terms of what type of workouts make more sense, like give example of reps n sets. I think I would understand better than hearing mechanical tension soo many times, lol.. Break it down like I am 5 years old

AMAZING JOB!!