Muscle Fiber Types Explained: Type 1, Type 2a, Type 2x | Muscle Physiology and Training Adaptations
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- čas přidán 15. 07. 2024
- Muscle Fiber Types Explained: Type 1 vs. Type 2a vs. Type 2x
Type 1 -Slow Twitch (slow twitch speed/ slow rate of force development)
* Small, red
* Recruited first in response to action potential
* Slow nerve conduction
* HIGHLY fatigue resistant (oxidative) good for endurance - high aerobic enzyme content
* Low Myosin ATPase (low contraction speed)
* Low power
* HIGH capillary & mitochondrial density
* Cross country, marathon
Type IIa
* Medium, white/red
* Larger motor units
* Fast contract/relax speed and nerve conduction velocity, intermediate power
* More anaerobic enzyme content
* Intermediate capillary and mitochondrial density
* Low myoglobin
Type IIx
* Largest motor units
* Largest diameter fiber, white
* High recruitment threshold
* Fast conduction and contraction
* Low fatigue resistance/ endurance
* High force and power
* Low capillary / mitochondrial density
* Large fibers
* Sprint, weightlifting
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0:00
0:06 Intro
0:29 Muscle Structure
1:05 Motor Units and Mosaic Distribution
2:15 Size Principle
3:30 Type I Fibers
5:59 Type IIa Fibers
8:52 Type IIx Fibers
10:46 Muscular Adaptations
12:00 Detraining
13:20 Muscle Fiber Hypertrophy
14:20 Myosin Isoform
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Your videos have been super helpful in studying for the CSCS exam. Thanks!
Glad to hear it! If you're not already make sure to also join my CSCS Prep Facebook group: facebook.com/groups/2415992685342170
As usual simple, clear and informative ! keep up the good work Matt !
Thank you!
As simple and didactic as it can be! Great as usual! Thanks Matt
Thank you!
just found your channel! great information and love people who put out genuinely good content that is backed by science! so refreshing lol
Thanks!
Extremely informative! You’re videos are top notch
Bro, really good job!
Totally easy to understand.
Yessss! Keep 'em coming.
Will do!
As a runner I was aware of slow-twitch and fast-twitch fibers. Nice to dive deeper here! As a CZcamsr I know how much goes into these videos! Keep posting - I just subscribed!
Thanks! Will be sure to keep posting thanks for subscribing
I'm taking my NASM-CPT exam in a week. While the test only touches the surface of this, your content has been extraordinarily helpful, especially because I always want to know more. Thank you!!
Best of luck!
So true I'm working on my ISSA
awesome explanation. very helpful. thank you!
I was literally looking for a video regarding this topic yesterday, and there you are! Thank you!
Excellent. Glad I could help
@@TheMovementSystem Hi Matthew, thank you for the video and yes, it made everything much simpler to comprehend. Will it be possible for you to cover Myosin and Actin in one of your videos? Please.
@@bhaskarjyabaruah1090 Yes I plan to make one soon
Awesome!!
Appreciate the content Matt!
You're welcome! Glad it's helpful for you
super helpful, thanks man
You are a great teacher. Thank you
Thank you!
very sample, thanks
!
Really thorough review!
Thanks!
Very clear and concise . Tq sir
where my 2a mains at? 💪
probably me haha (mostly i believe)
Subscribed!! keep posting :)
Thanks for subscribing!
I need to watch this video 10 times lol
Does the transition from a muscle fiber tipe to a superior one is like a liniar small change from type 1 to tipe 2 fiberes or it is straight from tipe 1 to type 2? Another way said: are there hibrid fiberes that slowly do transition from 1 type muscle fiberes to type 2?
Can I ask something sir? Should i bulk before weight training to get higher vertical jump or just weight training with enough protein eatting?
🤔✍️ 📝 - 14:24 jotting that down mate
Awesome content bro. I'm thinking about buying your program just a bit steep on price. Gonna have to save a bit first
👍🏼
Fast twitch dominant ❤
Hey mate, great video. Do you have any references that show Type 2x fibres transitioning back to Type 2a fibres after prolonged strength training??
There aren't a lot of longitudinal studies that follow a single group because it is expensive and difficult to get compliance, but there are a lot of studies that perform muscle biopsy on well trained athletes and show a very low proportion of 2x and a very high proportion of 2a.
I'm curious how much stronger IIx fibers are than IIa. If you have twice as much IIa fibers, will it be able to generate the same amount of force as IIx but still get the benefit of aerobic replenishment?
Hello mate,
ATPase activity is dominant in type 2 muscle fiber than type 1, therefore they are able to generate more force and rest of the things are relevant and appropriate
Go ahead 🙂 👍
Good point. Lower Myosin ATPase in Type 1 corresponds with lower Contraction speed
@@TheMovementSystem can I talk to you in private. I need some information regard CSCS course
@@abhisheksharma7084 Send me an email: mcasturo@gmail.com
What is the difference between Type IIb and Type IIx fibers?
does an abundance of type 2x muscles cause a muscle to be more dense/heavy? or vice versa?
I’m not sure
Hello, you mention that Type 1 fibers for high in myosin atpase, but the book says low. Just want classification so i have the correct information. Thank you!
is it possible to got from type I straight to type IIa?
Great video but how actually type 1 fibers increase? do that expand or synthesis due to Aerobic training
Type 1 muscle fiber growth is typically from hypertrophy (synthesis of new sarcomeres within an existing fiber) rather than hyperplasia (growth of new fibers)
can i train for both endurance and strength/power, is there a thing if i train for one i loss the other or they are not connected with each other and i can have both separately?
You can train both but to optimize one you would want to train it significantly more, which would probably decrease training response of the other.
could you please tell me the percentage of intensity for each type of muscle fiber? thanks in advance.
It doesn't work like that. If you do a 10 rep max with 70% intensity you could get into your type 2 fibers at the end of the set. If you do a 3RM with 93% intensity you'll probably be using type 2a/2x on all 3 reps. If you do 10 reps with 60% load you may not ever recruit your type 2s. It works on a spectrum as you can see.
Youre, as bostonians up here would say, "smat". Thank yuh
Hahah ya welcome
Hi Matt, just want to clarify. Muscle fibres are able to transit from one type to another, meaning for example, type I muscles can become IIa muscle fibres? which means the composition of muscle fibres can change? My lecturer in school was telling us that no way the muscle type fibre could be altered? is there something Im missing out here?
On short they can be altered. But also is more complex. Tipe 1 fiberes can't make hipertrofy so mutch but can become more stronger by improving theier energy sistems and also growing a little bit->structural changes.
Type 2 can grow mutch .We see type 2 fiberes usually on larger muscles when we look at someone.
Think it like this: So when you train at gym(growth or strenght) you also grow new muscle fiberes. This combined with size principe when you train tipe 2 you also train type1. But tipe 1 fatigue harder even at max force and they are not so stressed.Tipe 2 fatigue easyer so stress on them is bigger. So in time you will develope more muslce fiberes of tipe 2 if you go in the gym and train. So on short you can change the number of muscle fiberes overall AND you will change also the % between fiberes because you will increase more tipe 2 fiberes.But to do transition from tipe1 to tipe 2 and viceversa it is said is not possible structurally. But is possible just a little by how energy sistem in each muslce fibre will work
Im 90 % sure that this is correct as there are a lot of contrary opinnion on internet and also on researtch papers. But usualy how i told you is accepted.
idk much about fitness but tell me if im wrong, for strength and power training, 2x muscles are required right?
Yes heavy lifting will activate type 2a and 2x muscle fibers
Hi, the only thing that confuses me is that IIx turn to IIa even with resistance exercise -> wouldnt this result in lower max power output? How would this possibly be useful for an olympic weightlifter/thrower?
2x and 2a have similar power output but 2a is much more fatigue resistant so it's a beneficial adaptation overall
@@TheMovementSystem brilliant, thanks!
Do you have video about glycolysis and oxidative process ? I still feel confused about them
Or from which video should I watch first to understand this more logically? Thanks 🙏
Yes. This video: m.czcams.com/video/f62zuNfU28I/video.html&feature=emb_logo
Hi, Sir and thank you for the video.
During an 100m sprint, after the start, the muscle contraction rates needed are high so the slow oxidative Type I fibers cannot cope with this contraction rates. So what happens? We have violation of the muscle fiber recruitment rule which says that first the Type I are recruited, then the Type IIa and then the Type IIx?
I suppose the Type 2s are recruited instead because the Type 1s don’t have the capacity to handle the force exerted
@@jeems2066 nitpick, but I don’t think “instead” is the right word. Probably “in addition to”
So like, the body tries to recruit only the type 1s, finds that they’re not enough, and then recruits type 2
that means that I cannot change from muscle fiber type 1 to muscle fiber type 2A or 2B.
Can you please make a video about training type 2x fibers (legs to be speciy)...
Loved your video By the way.
It would be a short video. Squat really heavy weight (Above 90% 1RM)
@@TheMovementSystem thanks man.
@@utkarshsingh6096 You're welcome
Why myosin ATPase is high in Type1 muscle fibre?
Should say low.
what are the books in the background
Conscious Coaching, Supertraining, Science and Development of Muscle Hypertrophy, Designing Resistance Training Programs
@@TheMovementSystem wow thank you for all your help !
Aren't all of the fiber types recruited a long as you go to muscular failure or close to failure on an exercise.
Meaning it's not necessary to do a heavy 2 rep set to recruit certain fibers. They will kick in in when all other fibers have failed.
Yes that is true. If you fatigue type 1s even at a lower % 1RM you can activate type 2s.
Bruh am depressed now
Long story short: subscribe
Yup Subscribe for more cool videos like this!
Nice vid; Jesus loves you! ❤️