Any Actual Significant Physiologica Differences In...

At lighter loads, you won’t recruit all muscle fibers from the beginning, but as you fatigue you will have to call upon more muscle fibers to complete the set. The last few reps of a set will achieve 100% fiber recruitment. Shortening the mini rest periods when using myo reps will cause fatigue and full muscle recruitment to occur sooner. Taking long rest periods with light weights stops full muscle recruitment.
 
Right yes,
Small muscles fully recruit (not fully activate which which includes maximum rate coding, but just 'recruit' as in called up) around 50% of full effort, average muscles (torso, upper arms) about 60-85% of full effort and quads anywhere from 90-98% full effort.
So full 'recruitment' would occur when your supraspinal output (effort) reaches those levels during the set and the part of the ROM where it occurs. I would imagine just 'recruiting' isn't enough but also reaching high rate coding levels to really fatigue the fibers in those MU's.

"The relative contribution of motor unit recruitment to muscle force varies between muscles. In some hand muscles for example, all motor units are recruited at around 50% of maximum. In other muscles, such as the bicep brachii, deltoid, and tiblias anterior, motor unit recuitment continues upto 85% of the maximum force (Deluca, LeFever, McCue & Xenakis, 1982a; Kukulka & Clamann, 1981; Van Cutsem et al,. 1997)"
From p290, Neuromechanics of Human Movement 3rd Edition. Roger M. Enoka

Of course, maximum means momentary MVC or percent there-of, such as 1/2 way through the 11th rep with a 10RM, one would be displaying a 'fatigued' MVC, with full activation.
 
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I can't say for sure that's right, but that's what the studies showed. That a light weight to failure is the same hypertrophic stimulus as a heavy weight to failure. Since muscle fibers display the same full tension when fully activated, it makes sense to me.
there's this showing medium had actually more hypertrophy than heavy
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5131226/
And then Brad's study showing light and heavy had pretty much the same hypertrophy
https://www.ncbi.nlm.nih.gov/pubmed/25853914

Here's Brad's article about his study
http://www.lookgreatnaked.com/blog/does-light-load-training-build-muscle-in-experienced-lifters/

Borge even talked to me a bit about this via email last spring, he said he pretty much doesn't bother recommending heavy anymore. Here is his edited/updated thoughts on this on his page about myoreps http://borgefagerli.com/myo-reps-in-english/

All this also matches the studies on TTI I found many years ago and talked about on here.

So 'if' that is right, then the last day of your 15's has the same stimulation level as the last day of your 5's. Which is why I was thinking, it's not the loads going up over 6 weeks that are the 'magic' it's the 2 week blocks of ramped up stimulation via 'loadxreps', or work so to speak, so as long as you repeated that, it would be the same to the muscles as moving up in RM's each time.
Plus the way this summer I dropped my loads about 40%, increased 'fatigue' grew the best I have in years, did no RM increases, just added a little weight when I could as I went and it 'worked'. The lighter loads with more 'fatigue' trumped the heavier loads previously without the high fatigue.



Man hope that feels better, I'm battling quite a few nagging injuries too, so I feel for ya on that! Sounds like a good plan your on, hope that heals up for ya! Me, I'm a 'bad warmer upper', I just do a set first for a few reps to warm up and only on the scary exercises.



30.... man you lucky dog you lol. I remember 30... BARELY! I'm 52, ugh... where did the time go!
Autoregulation does seem very cool. It's really the only way to manage those ups and downs in energy and recovery that vary all the time.

Hehe ah cheers man yeah hopefully I recover soon.. hope yours get better too! And yeah I guess the body isn't as supple as when younger but age really doesn't mean much at all, just to adjust with the times I guess ay :)

Ah ok yeah I thiink I'm familiar with some of those studies, thanks heaps for posting those! Yeah I guess I meant that one is closer to full activation with all the 6RM reps than only on the last few with 15RM but yeah that's right when closer to fatigue it's the same effect as with a heavier weight. All very fascinating stuff..

That's really cool that you emailed with Borge! Yeah I'd be really interesting in understanding how to properly plan out a lighter weights cycle... I guess just progressing down to 10RM max (which actually is pretty heavy still to be honest..), but I'll still experiment with heavier weights assuming all is healthy. Loving this conversation by the way, I think it's exciting discussing these ideas.. just hoping we're doing it justice!
 
Hehe ah cheers man yeah hopefully I recover soon.. hope yours get better too! And yeah I guess the body isn't as supple as when younger but age really doesn't mean much at all, just to adjust with the times I guess ay :)

thanks! Man yes, at 52 I'm just glad I 'can' train at least medium heavy still!

Ah ok yeah I thiink I'm familiar with some of those studies, thanks heaps for posting those! Yeah I guess I meant that one is closer to full activation with all the 6RM reps than only on the last few with 15RM but yeah that's right when closer to fatigue it's the same effect as with a heavier weight. All very fascinating stuff..
Yes for sure, it's like a percentage thing
6RM all recruited from first rep
8RM probably all recruited from reps 2-8
15Rm probably all recruited from reps 11-15

Me too, great talking about this stuff again. I used to live this stuff. Physiology books, reading studies every day...


That's really cool that you emailed with Borge! Yeah I'd be really interesting in understanding how to properly plan out a lighter weights cycle... I guess just progressing down to 10RM max (which actually is pretty heavy still to be honest..), but I'll still experiment with heavier weights assuming all is healthy. Loving this conversation by the way, I think it's exciting discussing these ideas.. just hoping we're doing it justice!

I enjoy talking to Borge, I don't bug him often, but I know him from the old days on here. When all I knew was he was 'Blade'.
I think, but not sure, he keeps myo-reps loads similar for a while depending in trainee status. Beginner always about 30% etc.
Me, I'm going to stick around 12-15 Rm and use volume as in mini myo sets as my progressive means, then add weight to keep up with strength gains, repeat. Might as well try! I know last summer I ONLY used load increases 'as needed' and it 'worked' so that tells me I didn't have use higher RM's to gain for up to 3 months or so.
 
At lighter loads, you won’t recruit all muscle fibers from the beginning, but as you fatigue you will have to call upon more muscle fibers to complete the set. The last few reps of a set will achieve 100% fiber recruitment. Shortening the mini rest periods when using myo reps will cause fatigue and full muscle recruitment to occur sooner. Taking long rest periods with light weights stops full muscle recruitment.

That's why myoreps is so brilliant... safer for the joints (when done right) and creates the same stimulus as heavier weights... I just want to know if Borge has written more about recovery when doing myoreps, I've read alot of his autoregulation stuff but regarding when feeling like it's too taxing overall... I guess just keeping on top of the moment to moment reps and not pushing it too hard. Am feeling it today from yesterday's session (a fair bit of pelvic pain with my other stuff), so maybe I pushed it too hard yesterday..

I've been doing the 2 fatigue stops method, if hitting 5 reps in the first miniset, then 5 in the next, 4 in the next (1st fatigue stop), I would only stop when the reps dropped to 3 (Or if I reached 5 total minisets). But I may just stop when the reps lower only once...

Or even when it comes to fatigue stop 1, to actually increase my rest time (I've been just keeping the same rest..) which I think is what is supposed to be done then haha..
 
For 'me' it's all about how hard I push it. (burn out, recovery stuff) I've done (like I mentioned before) my version which is just rest pause where only 3 breaths were taken. My bench would be like this...
180x8, 3 breaths 3 reps, 3 breaths 1 rep 3 breaths, 1 rep.
that last '1 rep' would be HARD so I'd stop.
 
Me too, great talking about this stuff again. I used to live this stuff. Physiology books, reading studies every day...


I enjoy talking to Borge, I don't bug him often, but I know him from the old days on here. When all I knew was he was 'Blade'.
I think, but not sure, he keeps myo-reps loads similar for a while depending in trainee status. Beginner always about 30% etc.
Me, I'm going to stick around 12-15 Rm and use volume as in mini myo sets as my progressive means, then add weight to keep up with strength gains, repeat. Might as well try! I know last summer I ONLY used load increases 'as needed' and it 'worked' so that tells me I didn't have use higher RM's to gain for up to 3 months or so.

Yeah same, the sheer amount of hours I put into reading and studying all this stuff is beyond ridiculous hahaha.. still got massives piles of printed out papers from all over the net, HST ebook in there obviously hehe. Some really good printouts, some with shocking stuff XD

Ah yeah the Blade days :)

Yeah definitely worth giving a go, I've only ever had load as a primary focus so would be cool to scale up volume, then drop back and add weight when needed etc, that's really cool that you found that effective too so more incentive to explore that methodology!
 
For 'me' it's all about how hard I push it. (burn out, recovery stuff) I've done (like I mentioned before) my version which is just rest pause where only 3 breaths were taken. My bench would be like this...
180x8, 3 breaths 3 reps, 3 breaths 1 rep 3 breaths, 1 rep.
that last '1 rep' would be HARD so I'd stop.
Yeah exactly, I guess me just being more mindful at each rep and being absolutely dead honest with myself if I should end it there haha. It's like a painting "ahhh nah I'll add a bit more here, not quite finished yeeet", never finished! Haha
 
Yeah same, the sheer amount of hours I put into reading and studying all this stuff is beyond ridiculous hahaha.. still got massives piles of printed out papers from all over the net, HST ebook in there obviously hehe. Some really good printouts, some with shocking stuff XD

Man I hear ya, I have like 40 BB books, several physiology books, uncountable studies on my hard drive... fun though!

Yeah definitely worth giving a go, I've only ever had load as a primary focus so would be cool to scale up volume, then drop back and add weight when needed etc, that's really cool that you found that effective too so more incentive to explore that methodology!

Yes, I had that happen many years ago in the past too, lighter loads with more volume caused me to grow more than strength focus with heavy loads.
 
Yeah exactly, I guess me just being more mindful at each rep and being absolutely dead honest with myself if I should end it there haha. It's like a painting "ahhh nah I'll add a bit more here, not quite finished yeeet", never finished! Haha

Yes, realizing that it's better to have a 'less stimulatory' workout and stay feeling good for the next time, rather than kill it every time and end up ruing the whole cycle!
 
Man I hear ya, I have like 40 BB books, several physiology books, uncountable studies on my hard drive... fun though!



Yes, I had that happen many years ago in the past too, lighter loads with more volume caused me to grow more than strength focus with heavy loads.

Haha ah that's awesome, and really cool about lighter loads, and I also do think the individual comes into play here a bit. Of course there are principles, but it's quite clear some approaches just do work better for some and not others, it's definitely healthy and worth exploring i think a wide range of approaches, heck I even tried instinctive training a few months ago, and I tell it was actually really really fun! Nothing at all in the workouts/cycle was planned, I tried to record as little as possible (still ended up recording a bit haha couldn't help it..). Did whatever I 'felt' on the day, supersets, trisets, giant sets, multiple exercises at different angles, omnisets, high/low reps, dropsets, different rep cadences and tempos, just chucking all sorts of stuff together really.
It was purely just to mix it up and really allowed me to enjoy training and take it more lightly and have fun with it rather than it being a serious clinical task.

Yes, realizing that it's better to have a 'less stimulatory' workout and stay feeling good for the next time, rather than kill it every time and end up ruing the whole cycle!

YES amen to that!
 
cool, I've always wanted to try instinctive but I'm too OCD-ish to not plan and write things down lol
Yeah I am too, I reckon that's why it was so good for me to do :D was alot of fun. I'm thinking of doing that style every now and then just for variety (not results oriented, but purely as a reminder for the enjoyment of training)
 
[Warning, long post]
The question of why HST works requires us to consider what is it that the muscle cell is responding to. There are essentially three systems that resistance exercise stresses, neuromuscular, metabolic, and mechanical. The principles of HST take into consideration how these three systems work and how they respond to repeated bouts.

Neuromuscular
Think of the neuromusclular system as the rechargeable battery. It is influenced by intensity of contraction (the %RM you are using), duration of contraction (time under tension), and frequency of contraction (both rest between reps, sets and between bouts). HST means "hypertrophy specific" so we aren't specifically trying to increase the efficiency or capacity of the neuromusclar system. That's strength, power, and endurance so all we want to do is monitor it and make sure we don't drain it beyond our capacity to recharge it. [NOTE] Excitation contraction coupling is connected to anabolic signaling through calcium ion (Ca2+) fluctuations. Increases in Ca2+ likely stimulate mTOR signaling and protein synthesis by activating the Ca2+/calmodulin-dependent protein kinase α (CaMKKα). But generally we don't focus on Ca2+ to determine training variables.

Metabolic
Metabolic by products alter the internal milieu of the muscle cell and are produced by anaerobic metabolism. Anaerobic metabolism in working muscle leads to the accumulation of metabolic byproducts such as lactate, H+, inorganic phosphate (Pi), adenosine diphosphate (ADP), H2PO4-, and generates reactive oxygen and nitrogen species. Let's consider lactate as an example of how metabolic stress triggers anabolism. Lactate increases myogenin protein content and P70S6K phosphorylation. Lactate has also been shown to increase Pax7, MyoD, and mTOR phosphorylation. Interestingly, in-vitro work has shown lactate also significantly increases follistatin levels and decreases levels of myostatin in muscle cells. Additionally, lactate promotes differentiation in satellite cells. And we haven't even mentioned oxygen and nitrogen radicals... The point is, we know that increasing metabolic stress increases anabolic signaling and that these signaling pathways are mostly (but not entirely) redundant with mechanically induced signaling.

Mechanical
The ability of mechanical load/strain to induce hypertrophy was the first recognized stimulus. It occurs through a process called mechanotransduction. Muscle cells are sometimes referred to as mechanocytes. Mechanotransduction is the process of converting a mechanical stimulus into a chemical signal. In order to do this the cell must be able to "sense" mechanical forces. It does this with specialized protein structures that when stretched or distorted, initiate activation and phosphorylation of downstream signaling pathways (Examples include, but are not limited to, costameres, integrins, and G-protein-coupled receptors). In this way, a muscle cell can maintain its mass or grow in response to passive mechanical stress. The adaptive response to mechanical stress takes time as it involves the expression cellular organells and proteins to physically alter the structure and protein synthesizing efficiency and capacity of the cell.

Now you may be thinking, yeah but don't all bodybuilding routines do this? Yes, of course they do, which is why they all work for a lot of the people a lot of the time. HST isn't a routine though, it is a set of guiding principles that help us organize and plan out the neuromusclar, metabolic and mechanical stress in such a way as to try to optimize growth "over time". We start with metabolic stress, as this is both anabolic and prepares the tissues for heavier loads in the future. We continually increase the load which enhances and eventually replaces the anabolic stimulus caused by metabolic stress. We try to maintain the frequency and volume of training to both maximizes the rate of growth as well as reduce the likelihood of overreaching. Finally, once we've maxed out mechanical load, we remove both mechanical and metabolic stress just long enough to resensitize the system before we do it all over again. That is an explanation (their might be better ones out there) of why HST works.
 
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Thanks Bryan, very well put. It's good to go back to basics in terms of what the actual triggers are, and how the muscle cells respond to training.

I wonder if you could comment on quality of reps in an exercise and their effect. It's sort of on topic, asking the physiological effects of each type of training, but how those reps are performed and where the tension is placed seems to matter. Otherwise happy to start a new thread :)

Actually, I'll start a new thread as it veers a bit. Away I go!
 
@Bryan Haycock thanks for that more technical explanation. If you have time I do have some questions though.
  • You mention that the goal is not to maximize neuromuscular efficiency/capacity, would just more high intensity work shift to that direction?
  • Am I understanding the progression from Metabolic to Mechanical occurs by using the lower intensity but higher reps (typically 15s) and then incrementing up the weight through the bi-weekly into higher intensity but lower reps schemes (15s -> 10s -> 5s etc..)?
  • If you wanted to improve one (metabolic,mechanical) over the other would you just do more (sets, longer duration, frequency etc) or should you structure it differently?
  • HST (if I understand the above) progresses from one system to the next, what is gained or lost in training the systems concurrently?
 
@Bryan Haycock thanks for that more technical explanation. If you have time I do have some questions though.
  • You mention that the goal is not to maximize neuromuscular efficiency/capacity, would just more high intensity work shift to that direction?
  • Am I understanding the progression from Metabolic to Mechanical occurs by using the lower intensity but higher reps (typically 15s) and then incrementing up the weight through the bi-weekly into higher intensity but lower reps schemes (15s -> 10s -> 5s etc..)?
  • If you wanted to improve one (metabolic,mechanical) over the other would you just do more (sets, longer duration, frequency etc) or should you structure it differently?
  • HST (if I understand the above) progresses from one system to the next, what is gained or lost in training the systems concurrently?

In order to make your training strength-specific (aside from lifting heavy) you need to manipulate volume and frequency in order to ensure that the neuromuscular stimulus is appropriate. If your volume and frequency aren't dialed in your strength will stagnate or even decline. There is probably as much to say about strength specific training as there is about hypertrophy-specific training. :)

Yes, the prominent stimulus is metabolic when reps are high (i.e. lots of burning), and mechanical when weight is very heavy and reps are low. Moderate reps is a blend of both.

Your body will adapt in a specific fashion to what you make it do. So to emphasize metabolic adaptations, you must impose metabolic stress. The same is true for mechanical adaptations. Keep in mind however that as part of the adaptation process, the body and tissue will become for tolerant of the stress and the stimulus to adapt will decline over time.

If you want to combine high metabolic stress and high mechanical stress at the same time, I would recommend that you do your heavy sets first, then finish with one or two high rep sets. There is evidence that when combining two or more different stimuli, you get a compromise in adaptation. Much work has been done on concurrent strength and endurance training. When you combine them, you get both strength and endurance gains, but the gains in each are smaller than when either training strategy is performed in isolation. It is not entirely clear if strength and hypertrophy respond in a similar way as strength and endurance. This is because of redundant signaling pathways are involved in both strength and hypertrophy stimuli. Anecdotally, if you are a "trained" lifter, and want to peak for a strength event, at some point you must train solely for strength for maximum strength gains.
 
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