Waterbury's Thoughts: 10x10

Training Bodybuilding
61

[quote]pat36 wrote:
conwict wrote:
Lorisco, I think it isn’t a question of whether they “ARE” firing, but of the intensity at which they’re firing.

I can find some of his sources for this later.

I’d like to see some sources or research on this matter too. My intuition is telling me, what is known or thought is incomplete based on my own experiences. It seems to me that you cannot get 100% muscle fiber recruitment running at 100% capacity. It just doesn’t seem possible.

If it were possible, then going to failure at that capacity should be complete (momentary) muscle failure, not load specific muscle failure.

Here how I think it works, at least for the moment. Selecting a load for maximal stress either for intensity or endurance will recruit perhaps 70 to 80% of available motor units. Of those recruited about 15 - 20% of those are firing at 100% capacity while others are firing at a less capacity depending on their relation, i.e. “kind” of MU’s they are, to those being recruited 100%.

As the MU’s being recruited expire the load shifts more to the next most closely related MU’s. Since these MU’s are not suited ideally to the job, you begin to see form break down. Also since these surrounding MU’s were being used from the beginning, they will fail sooner.

Now if you shift the load, either going heavier or lighter you will be able to continue the set, but since the majority of the MU’s you are recruiting we recruited for the initial load they will expire quicker even though you have recruited some fresh ones. I am thinking of MU recruitment as a bell curve whose peak will move between high threshold and low threshold MU’s depending on load and speed.

It could be way off base, or I could be misunderstanding neural physiology completely, but it seems to make more sense to me then some of the current theories we’ve been discussing in this thread. I’ll take some thought on the matter if anybody cares to offer. I have no proof or time to research it properly; it just seems to make sense.
[/quote]

I believe the difference is the type of muscle units activated.

So you start out with heavy weight using most all your MU’s. As those fatigue, and the workload continues, the smaller endurance Type IIA fibers do more of the work. When you went to the last set and increased the load and got 1.5 reps, it was mostly the endurance fibers working or lifting the loading (not sure if the stronger fibers drop out or just produce less force). And the reason this can occur is because the endurance fibers recover very quickly, but they are not strong enough to lift the weight multiple times.

So I believe your experiment worked because you were not working the stronger fibers on the last set (1.5 reps). And this is why CW does not support that idea; because the stronger fibers (type IIB) have the greatest potential for strength and size increases. This is something that almost 100% of the experts agree on. So working the endurance fibers mostly, as in the last set, will not produce significant increases in strength and size.

62

[quote]Lorisco wrote:
Sentoguy wrote:

See but this was what I was arguing about earlier in the thread. The research that I have seen seems to suggest that, at least if the load remains constant, no fibers ever “drop out” as you (and CW) are suggesting. They only fatigue. There is a difference.

So, the type 11B fibers are still firing when the rep speed slows down, it’s just that because of fatigue factors (insufficient energy sources, metabolic byproducts, etc…) they are capable of producing less force, thus causing a decrease in bar speed. Sure, the intermediate fibers are still working as well, but the type 11B fibers don’t “drop out.”

Now, if you drop the weight (i.e. drop sets) the amount of force required to over come the resistance also lowers, thus allowing you to once again lift the resistance with more ease. This may actually cause the larger fibers to drop out (at least momentarily). However, the accumulation of metabolic byproducts also continues to increase, as well as the depletion of energy stores, and quickly causes fatigue again, as you continue the process repeats.

One possible explanation for Pat’s phenomenon is that when you drop the weight, this sudden drop in “intensity/stress” allows the type 11B fibers to recover (even if just a little). And, quite possibly, if you drop the weight enough the type 11B fibers may never fire. So, when you go back up, there are enough fibers that have somewhat recovered to be able to get one or two reps with the higher weight.

It’s also possible that he is either not truly going to concentric failure, or that he is using additional muscles to perform the reps with the higher weights. We don’t actually have a video of him doing this, nor could we really tell from a video even if we had one. But, personally I’ll take his word that he is doing this all legitimately.

So, it’s probably any of our guesses why or how this phenomenon occurs. I’d really like to hear what some of the more educated individuals on this site would have to say about this (Poliquin, CW, CT, etc…).

Really though as interesting as this theorizing is, if it doesn’t result in, well results, then it’s really not all that useful.

Good training,

Sentoguy

Do you have any links to the studies you are referring to? My understanding has always been that the Type IIB fibers dropped out, but if they are still there working, just with less force, that seems to change everything. The difference would be that continuing to train a muscle fiber that was fatigued would work well for strength and hypertrophy increases, but not so well for neural skills training for sports.

So I would be very interested to see those studies.

[/quote]

I do have the study that I’m referring to, I saved a copy of it in PDF format, so I don’t think that I can link to it here. But, I actually got the study during a very in depth and enlightening discussion between myself and Tim Henriques about the subject of MU recruitment. I’ll try to find that thread and put up a link to the article.

Actually, here is the link. If it doesn’t work, it’s also on page 5 of the “Fast To Big” article discussion.

http://jn.physiology.org/...t/90/5/2919.pdf

Good Training,

Sentoguy

63

Thanks sentoguy.

This is very interesting. Sounds like ballistic reps lower the high MU recruitment threshold and therefore technically recruit more high threshold MU throughout the set than slower reps.

So my question would be; why does CW state to stop the set when speed slows? In a non-ballistic rep speed set that is where most of the high threshold MU are recruited; the last few reps. So wouldn’t it be the best of both worlds to use ballistic rep speed on all reps, but go to near failure on all sets?

64

[quote]Lorisco wrote:
In a non-ballistic rep speed set that is where most of the high threshold MU are recruited; the last few reps. So wouldn’t it be the best of both worlds to use ballistic rep speed on all reps, but go to near failure on all sets?
[/quote]

This is not correct. You DON’T recruit high threshold MUs at the end of the set when your force is low. I keep trying to get this point across. Force is positively correlated with MU recruitment. When force is highest, MU recruitment is highest.

Slow contractions, for the most part, don’t even tap into the highest threshold MUs if the load is anything less than 85% of 1RM. Even then it’s still limited because if you’re ever lifting slower than max speed, you’re doing so at the expense of MU recruitment.

The problem is that most coaches, and most people, don’t have a thorough understanding of how MUs are recruited and the physiological limitations of muscle fibers during recruitment.

65

[quote]Chad Waterbury wrote:
Lorisco wrote:
In a non-ballistic rep speed set that is where most of the high threshold MU are recruited; the last few reps. So wouldn’t it be the best of both worlds to use ballistic rep speed on all reps, but go to near failure on all sets?

This is not correct. You DON’T recruit high threshold MUs at the end of the set when your force is low. I keep trying to get this point across. Force is positively correlated with MU recruitment. When force is highest, MU recruitment is highest.

Slow contractions, for the most part, don’t even tap into the highest threshold MUs if the load is anything less than 85% of 1RM. Even then it’s still limited because if you’re ever lifting slower than max speed, you’re doing so at the expense of MU recruitment.

The problem is that most coaches, and most people, don’t have a thorough understanding of how MUs are recruited and the physiological limitations of muscle fibers during recruitment. [/quote]

You know Chad I thought the same thing, until I read that study that I posted above. According to that study, fatigue lowers MU recruitment thresholds just as ballistic reps do. The results of that study also suggest that the HTMU’s don’t drop out like I had previously thought, but instead fatigue, thus allowing them to produce less force.

What would your response be to the researchers who conducted that study? If there is something wrong with the study then personally I’d like to hear what it is. You’re admittedly much more knowledgeable than I am on this subject.

Good training,

Sentoguy

66

[quote]Lorisco wrote:
Thanks sentoguy.

This is very interesting. Sounds like ballistic reps lower the high MU recruitment threshold and therefore technically recruit more high threshold MU throughout the set than slower reps.

So my question would be; why does CW state to stop the set when speed slows? In a non-ballistic rep speed set that is where most of the high threshold MU are recruited; the last few reps. So wouldn’t it be the best of both worlds to use ballistic rep speed on all reps, but go to near failure on all sets?
[/quote]

Actually I am not suggesting that a non ballistic rep speed set will recruit more HTMU’s. Nor does that study necessarily suggest this. It simply illustrates that fatigue can lower MU recruitment thresholds, thus recruiting additional MU’s that would not have otherwise been called into play.

Ballistic reps also lower recruitment thresholds and likewise I think that Chad deserves a lot of credit for brining the importance of ballistic reps into the lime light. I know that I’ve utilized ballistic concentric contractions ever since reading some of his earlier articles on it’s importance.

But, I do agree personally that ballistic reps taken until failure is a potent combination of MU recruitment methods. This is currently what I am doing and it seems to be working quite effectively for me.

Not saying that CW’s MRT program won’t work, I honestly believe it will. It’s just the I personally feel that what I’m currently doing is more efficient (and I personally like pushing the envelope). I only perform between 11-30 (and only above 20 on a couple exercises) total reps per body part and have been seeing great improvements in both size and strength.

If someone else chooses to do MRT, or FTB then I say more power to them. I haven’t personally tried MRT so I can’t comment on that, but did play around with FTB for a little while and did think that it was good. Like I said it’s just that for my personal taste I have switched to doing what I’m currently doing.

Good training,

Sentoguy

67

[quote]Sentoguy wrote:
Chad Waterbury wrote:
Lorisco wrote:
In a non-ballistic rep speed set that is where most of the high threshold MU are recruited; the last few reps. So wouldn’t it be the best of both worlds to use ballistic rep speed on all reps, but go to near failure on all sets?

This is not correct. You DON’T recruit high threshold MUs at the end of the set when your force is low. I keep trying to get this point across. Force is positively correlated with MU recruitment. When force is highest, MU recruitment is highest.

Slow contractions, for the most part, don’t even tap into the highest threshold MUs if the load is anything less than 85% of 1RM. Even then it’s still limited because if you’re ever lifting slower than max speed, you’re doing so at the expense of MU recruitment.

The problem is that most coaches, and most people, don’t have a thorough understanding of how MUs are recruited and the physiological limitations of muscle fibers during recruitment.

You know Chad I thought the same thing, until I read that study that I posted above. According to that study, fatigue lowers MU recruitment thresholds just as ballistic reps do. The results of that study also suggest that the HTMU’s don’t drop out like I had previously thought, but instead fatigue, thus allowing them to produce less force.

What would your response be to the researchers who conducted that study? If there is something wrong with the study then personally I’d like to hear what it is. You’re admittedly much more knowledgeable than I am on this subject.

Good training,

Sentoguy[/quote]

Give me a link to the research in question and I’ll explain.

68

[quote]Sentoguy wrote:

Actually I am not suggesting that a non ballistic rep speed set will recruit more HTMU’s. Nor does that study necessarily suggest this. It simply illustrates that fatigue can lower MU recruitment thresholds, thus recruiting additional MU’s that would not have otherwise been called into play.

Ballistic reps also lower recruitment thresholds and likewise I think that Chad deserves a lot of credit for brining the importance of ballistic reps into the lime light. I know that I’ve utilized ballistic concentric contractions ever since reading some of his earlier articles on it’s importance.

But, I do agree personally that ballistic reps taken until failure is a potent combination of MU recruitment methods. This is currently what I am doing and it seems to be working quite effectively for me.

Not saying that CW’s MRT program won’t work, I honestly believe it will. It’s just the I personally feel that what I’m currently doing is more efficient (and I personally like pushing the envelope). I only perform between 11-30 (and only above 20 on a couple exercises) total reps per body part and have been seeing great improvements in both size and strength.

If someone else chooses to do MRT, or FTB then I say more power to them. I haven’t personally tried MRT so I can’t comment on that, but did play around with FTB for a little while and did think that it was good. Like I said it’s just that for my personal taste I have switched to doing what I’m currently doing.

Good training,

Sentoguy[/quote]

Sentoguy,

You know I respect your posts and your overall interest in the subject, but you’re still missing the point.

You must tap into your largest MUs if you want the fastest strength/size gains. You must also fatigue those MUs. THIS is where people get lost. Going to failure does NOT fatigue the largest MUs. Such a statement completely goes against the size principle and the clear relationship between force and MU recruitment. When you fatigue (speed slows down) you’re generating less force. When you’re generating less force the largest MUs have dropped out (fatigued) and the smaller MUs are doing the brunt of the work. By going to failure you’re only overloading the smaller muscle fibers.

The way to fatigue your largest MUs is to perform more sets of lower reps. Your largest MUs can’t maintain max recruitment for more than 15s. So any set longer than that is relying on smaller MUs. For most people, 25-30 total reps is ideal for size strength, that’s why 5x5 is so popular, and that’s why 10x3 is so popular. Both methods result in sets that last less than 15s, and both rely on enough sets to fatigue those largest MUs.

What I’m doing is tweaking those systems so people don’t get caught up in a target number of reps with each set. 25 total reps for the squat is great. But you’re better off terminating each set when the speed slows down, rest, then perform another set until you reach 25 reps. If you do this, all 25 reps will recruit virtually all your MUs.

Hope this helps. I just submitted an article to clear up this confusion (let’s hope it works this time)!

69

[quote]Chad Waterbury wrote:

Sentoguy,

You know I respect your posts and your overall interest in the subject, but you’re still missing the point.

You must tap into your largest MUs if you want the fastest strength/size gains. You must also fatigue those MUs. THIS is where people get lost. Going to failure does NOT fatigue the largest MUs. Such a statement completely goes against the size principle and the clear relationship between force and MU recruitment. When you fatigue (speed slows down) you’re generating less force. When you’re generating less force the largest MUs have dropped out (fatigued) and the smaller MUs are doing the brunt of the work. By going to failure you’re only overloading the smaller muscle fibers.

The way to fatigue your largest MUs is to perform more sets of lower reps. Your largest MUs can’t maintain max recruitment for more than 15s. So any set longer than that is relying on smaller MUs. For most people, 25-30 total reps is ideal for size strength, that’s why 5x5 is so popular, and that’s why 10x3 is so popular. Both methods result in sets that last less than 15s, and both rely on enough sets to fatigue those largest MUs.

What I’m doing is tweaking those systems so people don’t get caught up in a target number of reps with each set. 25 total reps for the squat is great. But you’re better off terminating each set when the speed slows down, rest, then perform another set until you reach 25 reps. If you do this, all 25 reps will recruit virtually all your MUs.

Hope this helps. I just submitted an article to clear up this confusion (let’s hope it works this time)![/quote]

Hi Chad,

Like I’ve said many times before, I have a great deal of respect for you and your unorthodox, yet effective programs. I also understand what you’re trying to do, I’ve understood since you first wrote your article “Everything is about to change”. Remember my response to Tim Henriques where you complimented me on my understanding what you were trying to get across?

I had honestly thought the same thing prior to your writing that article. But, through many in depth discussions (and more importantly reading the article I posted above concerning fatigue and MU recruitment) I realized that perhaps my understanding of why speed would decrease wasn’t as complete as I had previously thought.

I am not arguing with you by the way, just a little confused as I’ve been handed evidence that my previous notions concerning what occurs during a set to failure (fatigue) may have been incorrect, or at least incomplete. Like I said before though, you’re the expert on the subject.

So, what is your response to the results of the article that I posted above? Was the method used by the researchers flawed in some way? Does your research suggest that isometric contractions result in a different order or stimulation of MU’s than dynamic contractions?

Could you also elaborate on what you meant by suggesting that going to failure does not fatigue the largest MU’s, but then a couple sentences later suggest that the reason rep speed slows down towards the end of a set to failure is due to the largest MU’s being fatigued? That just seems like a contradictory statement. Are you saying perhaps that the set to failure doesn’t provide enough fatigue to stimulate growth?

Thanks for the response.

Sentoguy

70

[quote]Sentoguy wrote:

Could you also elaborate on what you meant by suggesting that going to failure does not fatigue the largest MU’s, but then a couple sentences later suggest that the reason rep speed slows down towards the end of a set to failure is due to the largest MU’s being fatigued? That just seems like a contradictory statement. Are you saying perhaps that the set to failure doesn’t provide enough fatigue to stimulate growth?

Thanks for the response.

Sentoguy[/quote]

This is the key point and the focus of your confusion. Let me try a different angle in an effort to help you understand. I’m doing this because you have a sharp mind and your intentions are good.

As the size principle states, the path to your largest MUs is through your smaller MUs. You can’t get to your largest MUs unless you can also recruit your smaller ones. When you fatigue your smaller MUs, you’ve essentially set up a roadblock to reach your larger ones.

Second, I should state the issue more clearly with failure training. If you’re training slow, you’re never recruiting the largest MUs unless you’re lifting a 1RM. So the largest MUs aren’t dropping out - they were never recruited in the first place. If, however, you’re training with maximal acceleration you can recruit the largest MUs as long as the load is at least 60% of your 1RM. Bottom line: when I say “largest MUs” have dropped out, this is only the case if they were recruited in the first place. With many examples that people typically give, the largest MUs were never recruited.

Third, you’ve gotta think about a muscle’s pH levels (an issue most people don’t bring up because they don’t understand it). When you’re approaching/reaching failure your muscles become much more acidic (pH drops). This is why your muscles burn. When your muscle’s pH drops, it reduces your ability to produce maximal force by inhibiting cross bridge formation. So, once again, when you go to failure - especially with higher reps - you’ve acidified your muscles and reduced their ability to produce max force.

This is why lower rep sets with more total sets is a better approach.

Finally, you can find pieces of research to basically support any argument. I’m privy to the best neuroscience research in the world and what I’m saying is supported by that research. I still don’t know what study you’re referring to since you didn’t give me a link to it.

That’s all. I’ll continue to cover these issues in subsequent articles. I’m off like a prom dress.

71

Thanks again for the response CW, and thanks for clarifying what you meant.

[quote]Chad Waterbury wrote:

As the size principle states, the path to your largest MUs is through your smaller MUs. You can’t get to your largest MUs unless you can also recruit your smaller ones. When you fatigue your smaller MUs, you’ve essentially set up a roadblock to reach your larger ones.
[/quote]

Interesting, I’d never heard that fatiguing your smaller MU’s sets up a “roadblock” to reaching the larger ones. That certainly is an important detail that I wish I had previously been aware of.

Okay, so once again maximal acceleration lowers MU recruitment thresholds. I have read studies that did illustrate this, and after reading some of your earlier (and later) articles about the importance of this I’ve been utilizing it with great success in my training.

Right I hear you. The ph levels are raised due to build up of lactic acid which is a byproduct of anaerobic glycolysis. But, isn’t lactic acid also a trigger for growth hormone release? So, from a hormonal standpoint might going to failure be beneficial? Might utilizing failure training in conjunction with maximal acceleration provide both maximal MU recruitment and the hormonal benefits of lactic acid buildup?

[quote]
This is why lower rep sets with more total sets is a better approach.

Finally, you can find pieces of research to basically support any argument. I’m privy to the best neuroscience research in the world and what I’m saying is supported by that research. I still don’t know what study you’re referring to since you didn’t give me a link to it.

That’s all. I’ll continue to cover these issues in subsequent articles. I’m off like a prom dress. [/quote]

Yes I understand you’ve probably read exponentially more research than I have and once again fully admit that your knowledge on this subject is far greater than my own. Honestly that point about fatiguing the smaller MU’s causing a roadblock to the higher MU’s was very enlightening in and of itself.

The study that I’m referencing is the one I posted above for Lorisco. I’ll post it again here in case you’re interested.

http://jn.physiology.org/cgi/reprint/90/5/2919.pdf

Thanks again for the response and I look forward to reading the future articles.

Good training,

Sentoguy

P.S. Mods, I copied the link to the article and it worked when I tried it. There also is no specific site where I can copy the actual address from, only a pdf file, which I don’t know how to attach to a post. Sorry if it’s not complete.

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[quote]Chad Waterbury wrote:

The way to fatigue your largest MUs is to perform more sets of lower reps. Your largest MUs can’t maintain max recruitment for more than 15s. So any set longer than that is relying on smaller MUs. For most people, 25-30 total reps is ideal for size strength, that’s why 5x5 is so popular, and that’s why 10x3 is so popular. Both methods result in sets that last less than 15s, and both rely on enough sets to fatigue those largest MUs.

What I’m doing is tweaking those systems so people don’t get caught up in a target number of reps with each set. 25 total reps for the squat is great. But you’re better off terminating each set when the speed slows down, rest, then perform another set until you reach 25 reps. If you do this, all 25 reps will recruit virtually all your MUs.

[/quote]

Chad, I think I need to just outline the process as I understand it and have you show me where I’m wrong:

  1. Using the size principle; you recruit small MU’s and then HTMU’s as the force required increases.

  2. Fast concentric rep speed requires a lot of force, which in turn requires more HTMU’s.

  3. Once the HTMU fatigue (after 15 seconds), you are left with the smaller MU’s and that is when rep speed slows.

  4. After rep speed slows you cannot exert enough force to recruit the HTMU’s unless you rest to allow them to recover

  5. If you continue reps after rep speed slows you are only working the small UM’s, which do not have the potential for increases in hypertrophy and strength like the HTMU’s.

  6. Multiple sets of reps until rep speed slows are required to get enough volume to induce increases in strength and size

If this is correct, I have a question; if you perform fast rep speed sets to failure, will your small MU’s gain in strength and size as well? From a pure hypertrophy standpoint, wouldn’t it be advantageous to work all MU’s, not just the HTMU’s?

73

[quote]Sentoguy wrote:

Right I hear you. The ph levels are raised due to build up of lactic acid which is a byproduct of anaerobic glycolysis. But, isn’t lactic acid also a trigger for growth hormone release? So, from a hormonal standpoint might going to failure be beneficial? Might utilizing failure training in conjunction with maximal acceleration provide both maximal MU recruitment and the hormonal benefits of lactic acid buildup?

Good training,

Sentoguy[/quote]

First, I’ll address the statement above. When I talked about muscle acidification I wasn’t talking about lactic acid. I was talking about the accumulation of protons (H+) due to the breakdown of glycogen and glucose. It appears that this is what’s interfering with cross bridge formation, not lactic acid as previously thought. Lactic acid is another by-product that’s produced to support muscle contractions.

As for the lactic acid/GH link, it’s so low that it’s not even worth worrying about.

The key is to keep thinking about the “bridge” between your smaller and bigger MUs. When you train to failure, it’s very difficult to produce as much force in subsequent sets, even when the rest periods are long. This “blocking” is the reason why.

Finally, I looked over the paper. I wasn’t privy to it and I know why: it didn’t demonstrate anything new. That’s not because it was a bad paper (it was actually fairly good), it’s just that it simply supports what we already know.

The conclusion of the paper was that the recruitment threshold is lowered as more force is required. That’s been demonstrated for 30 years. Second, it shows, once again, that the size principle holds true (that’s important because it’s the cornerstone of my argument): as more force was required, more MUs were activated.

Look closely at figure 2 in the paper. Notice how the highest level of MU recruitment was at the very beginning of the set where, of course, the force was highest. This supports what I’m saying.

And there are some other nuances that I won’t discuss with great detail, but I’ll hit on a few. One being that the contractions were only 20% of MVC; the second being that the contractions were isometric. In any case, the paper doesn’t refute one thing I’m saying: it supports it.

Thanks, and I hope this helps.

74

[quote]Lorisco wrote:

Chad, I think I need to just outline the process as I understand it and have you show me where I’m wrong:

  1. Using the size principle; you recruit small MU’s and then HTMU’s as the force required increases.

  2. Fast concentric rep speed requires a lot of force, which in turn requires more HTMU’s.

  3. Once the HTMU fatigue (after 15 seconds), you are left with the smaller MU’s and that is when rep speed slows.

  4. After rep speed slows you cannot exert enough force to recruit the HTMU’s unless you rest to allow them to recover

  5. If you continue reps after rep speed slows you are only working the small UM’s, which do not have the potential for increases in hypertrophy and strength like the HTMU’s.

  6. Multiple sets of reps until rep speed slows are required to get enough volume to induce increases in strength and size

If this is correct, I have a question; if you perform fast rep speed sets to failure, will your small MU’s gain in strength and size as well? From a pure hypertrophy standpoint, wouldn’t it be advantageous to work all MU’s, not just the HTMU’s?

[/quote]

Points 1-6 are exactly right. Your question, at the end, is where your confusion sits so I’ll answer it.

You can gain size and strength by overloading the smaller muscle fibers. This is why cyclists have very large thighs - proof that you can hypertrophy the smaller muscle fibers.

With each rep that’s close to maximum force capacity, all of your recruitable MUs are recruited. The largest MUs drop out when you fatigue. Your question is “why don’t we make the smaller fibers drop out too?” The reason, as I mentioned in an earlier post is that it limits your ability to once again reach the largest MUs (ie, generate maximum force) in subsequent sets. Therefore, subsequent sets continue to overload your smaller muscle fibers.

You WILL induce enough fatigue to the smaller MUs to derive strength and size gains if you simply stop when the largest MUs have dropped out. This is where my set/rep guidelines came from. Just because you’re not forcing your smaller MUs to drop out doesn’t mean they can’t grow. Remember, you can’t selectively recruit your largest MUs - all other MUs are along for the ride and they’re contributing to your force output. But if you do overload the smaller fibers to the point where they drop out you’re gonna have a helluva tough time reaching your largest MUs on subsequent sets.

KEY POINT: fatigue and failure are not synonymous: failure is due to fatigue, but fatigue can occur without failure. Fatigue is simply defined as an inability for a MU to perform at it’s highest capacity. If you performed 20 sets of one rep with 85% of your 1RM at max speed you’d recruit all of your MUs with each rep. And if you analyze the force generating capacity of the smaller MUs after that session you’d see that it’s lower. That’s becasue the recruitment of the smaller MUs along with the largest MUs was sufficient to fatigue the smaller MUs.

Hope this helps.

I encourage you all to spread this information. If you do I’ll be forever grateful because it’ll help keep me off the forums. That way, I can devote more time to writing articles where thousands of people can read what I’m saying.

75

[quote]Chad Waterbury wrote:
Lorisco wrote:

Chad, I think I need to just outline the process as I understand it and have you show me where I’m wrong:

  1. Using the size principle; you recruit small MU’s and then HTMU’s as the force required increases.

  2. Fast concentric rep speed requires a lot of force, which in turn requires more HTMU’s.

  3. Once the HTMU fatigue (after 15 seconds), you are left with the smaller MU’s and that is when rep speed slows.

  4. After rep speed slows you cannot exert enough force to recruit the HTMU’s unless you rest to allow them to recover

  5. If you continue reps after rep speed slows you are only working the small UM’s, which do not have the potential for increases in hypertrophy and strength like the HTMU’s.

  6. Multiple sets of reps until rep speed slows are required to get enough volume to induce increases in strength and size

If this is correct, I have a question; if you perform fast rep speed sets to failure, will your small MU’s gain in strength and size as well? From a pure hypertrophy standpoint, wouldn’t it be advantageous to work all MU’s, not just the HTMU’s?

Points 1-6 are exactly right. Your question, at the end, is where your confusion sits so I’ll answer it.

You can gain size and strength by overloading the smaller muscle fibers. This is why cyclists have very large thighs - proof that you can hypertrophy the smaller muscle fibers.

With each rep that’s close to maximum force capacity, all of your recruitable MUs are recruited. The largest MUs drop out when you fatigue. Your question is “why don’t we make the smaller fibers drop out too?” The reason, as I mentioned in an earlier post is that it limits your ability to once again reach the largest MUs (ie, generate maximum force) in subsequent sets. Therefore, subsequent sets continue to overload your smaller muscle fibers.

You WILL induce enough fatigue to the smaller MUs to derive strength and size gains if you simply stop when the largest MUs have dropped out. This is where my set/rep guidelines came from. Just because you’re not forcing your smaller MUs to drop out doesn’t mean they can’t grow. Remember, you can’t selectively recruit your largest MUs - all other MUs are along for the ride and they’re contributing to your force output. But if you do overload the smaller fibers to the point where they drop out you’re gonna have a helluva tough time reaching your largest MUs on subsequent sets.

KEY POINT: fatigue and failure are not synonymous: failure is due to fatigue, but fatigue can occur without failure. Fatigue is simply defined as an inability for a MU to perform at it’s highest capacity. If you performed 20 sets of one rep with 85% of your 1RM at max speed you’d recruit all of your MUs with each rep. And if you analyze the force generating capacity of the smaller MUs after that session you’d see that it’s lower. That’s becasue the recruitment of the smaller MUs along with the largest MUs was sufficient to fatigue the smaller MUs.

Hope this helps.

I encourage you all to spread this information. If you do I’ll be forever grateful because it’ll help keep me off the forums. That way, I can devote more time to writing articles where thousands of people can read what I’m saying. [/quote]

So based on this information, when working a drop set, taking each phase to failure, i.e. cannot generate enough force to move the load, when I get to the lower weights are the HTMU’s not recruited and hence given a chance to recover even though the set hasn’t stopped?
This would also mean you can work lighter load to failure and be able to immediately jump to very heavy loads for maximum recruitment.

Actually this would an interesting experiment where you fatigue your lower threshold MU’s maximally, and then lift the heavy loads. What should happen, is once the HTMU’s cease producing enough force, the set stops because you can’t move it.

I’ll spread the word as my understanding increases. But I think we like having you participate in the forums so drop in sometimes.

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[quote]conwict wrote:
100%-recruitment seems a very iffy thing really.
[/quote]

Yes - you’re NOT going to fatigue all MUs. Period. There are always some that lie “dormant,” even in a 1RM. Many call them “survival” fibers, referring to the fact that it really takes a life or death situation to activate them (you know, the classic “100 lb woman lifts a car off her trapped kid” example?).

Thibs mentions frequently that fibers remained untouched.

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[quote]pat36 wrote:
conwict wrote:
Of those recruited about 15 - 20% of those are firing at 100% capacity while others are firing at a less capacity
[/quote]

No - MUs work according to the “all or none” law. They either fire at full strength, or they don’t fire at all. The difference is in the number of MUs recruited. According to the all or none law, you’d think that something like walking would be extremely difficult, but this is not the case, because there are few fibers firing (but those that are firing are firing at full strength). As the demand increase, more and more units are called upon (so, sprinting calls upon more units than walking).

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[quote]Chad Waterbury wrote:
You DON’T recruit high threshold MUs at the end of the set when your force is low.
[/quote]

This is what confuses me. This says that Zatsiorky was wrong, and the repeated effort method does not touch the HTMUs. Doesn’t the repeated effort method state that the HTMUs can be called on as a last resort, provided that there is a certain minimum load (like 70-80%)? (The RE method confuses me anyway, because it goes totally against my understanding.)

I came into the this thread with the following understanding:

1-The size principle states that the smallest MUs are recruited first
2-As the load increases closer to maximum, the number or MUs recruited increases.
3-The more powerful MUs are recruited as the load becomes heavier
4-A certain load MUST be attempted in order for the HTMUs to be recruited
5-Merely exhausting a muscle will not recruit all MUs (so the repeated effort method CAN’T recruit the HTMUs)
6-In the final reps before failure, the HTMUs have dropped out, leaving the smaller, more enduring (but weaker) ones to handle the job. Since they are weaker, is part of the reason why the final reps are more difficult.
7-HTMUs CANNOT be recruited as a “last resort” because the size principle would preclude this from happening. If they weren’t recruited at the beginning of the set, the load was not heavy enough to activate them in the first place, so they will never get involved. The smaller MUs must handle the job themselves.

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[quote]Dark_Knight wrote:
Chad Waterbury wrote:
You DON’T recruit high threshold MUs at the end of the set when your force is low.

This is what confuses me. This says that Zatsiorky was wrong, and the repeated effort method does not touch the HTMUs. Doesn’t the repeated effort method state that the HTMUs can be called on as a last resort, provided that there is a certain minimum load (like 70-80%)? (The RE method confuses me anyway, because it goes totally against my understanding.)

I came into the this thread with the following understanding:

1-The size principle states that the smallest MUs are recruited first
2-As the load increases closer to maximum, the number or MUs recruited increases.
3-The more powerful MUs are recruited as the load becomes heavier
4-A certain load MUST be attempted in order for the HTMUs to be recruited
5-Merely exhausting a muscle will not recruit all MUs (so the repeated effort method CAN’T recruit the HTMUs)
6-In the final reps before failure, the HTMUs have dropped out, leaving the smaller, more enduring (but weaker) ones to handle the job. Since they are weaker, is part of the reason why the final reps are more difficult.
7-HTMUs CANNOT be recruited as a “last resort” because the size principle would preclude this from happening. If they weren’t recruited at the beginning of the set, the load was not heavy enough to activate them in the first place, so they will never get involved. The smaller MUs must handle the job themselves.

[/quote]

The RE method CAN recruit your HTMUs provided the lifting speed is as fast as possible and the load is sufficient (>60% of 1RM).

Where I separate from other RE method recommendations is at the end of the set. When you push to failure you’re overloading your smaller MUs. In some cases (muscular endurance) that can be a good thing. But for maximal size/strength it’s not optimal, in my opinion.

80

[quote]Chad Waterbury wrote:
The RE method CAN recruit your HTMUs provided the lifting speed is as fast as possible and the load is sufficient (>60% of 1RM).[/quote]

But doesn’t Zatsiorsky state that the HTMUs are recruited in the FINAL reps before failure, this “maximum tension/force in a fatigued state”? I thought the whole concept behind RE was that the fatigue requires that HTMUs jump in to complete the action, even if the load and previous reps did not initially warrant it. (I have not read Zatsiorsky, so I’m not sure if I’ve got this correct. But my current understanding of it does not make sense to me - but if I DO have it straight, I disagree with Zatsiorsky.)

[quote]Chad Waterbury wrote:
When you push to failure you’re overloading your smaller MUs.[/quote]

This is exactly what I thought, and this is why I don’t understand why it is said that RE recruits HTMUs in the final reps. Is this not what Zatsiorsky said?

(I’ve actually been intending to get a copy of Science and Practice of Strength Training to read Zatsiorsky for myself.)

I actually had a discussion about this the first week of September, over on the Rosstraining.com forum. My thoughts were this:

Type II fibers primarily power through the set, and gas out very quickly. Type I fibers then take over, and exert the max force they are capable of producing (while in a fatigued state). Since they are far weaker than type II fibers, this is why the last 2 reps or so move so slow and are so hard - because the type IIs dropped out and left the type I fibers to finish the job, a job they are just barely capable of handling. Further, it makes even more sense when you think about the current, very common recommendation to terminate a set 1-2 reps short of failure (generally recommended as a method to lessen strain on the CNS). Because, at this point, the type II fibers are done, and pushing it further is not going to strengthen them any more.

Unless, I’m mistaken, this is exactly Chad’s position. (And please correct me if I am mistaken.)

[quote]Chad Waterbury wrote:
In some cases (muscular endurance) that can be a good thing. But for maximal size/strength it’s not optimal, in my opinion.
[/quote]

I’ve been thinking a lot about this recently, and I’m finding that my position is in line with yours.