Why Aren't The Last Reps Easiest?

Tim_Henriques · June 23, 2007, 3:24am

Sento - I never said that force wasn’t a factor in MU recruitment, I just said it wasn’t the only factor and that fatigue was an important factor.

Here is a question for you that I would like your take on. You mentioned isometrics earlier. Let’s say I do a challenging isometric contraction for 20-30 seconds. For example, I hold 135 lbs in the mid point of a barbell curl for 20-30 seconds with no movement before I fail.

Using your version of the size principle, explain what you see happening in the muscle regarding motor unit recruitment, given that the external force is constant (since there is no movement) and that we know that the type II muscle fibers can’t contract for 20-30 seconds straight. If it matters say this person’s 1RM in the curl is 160 or so. Thanks for your thoughts.
Tim

Scotacus · June 23, 2007, 3:39am

[quote]Tiribulus wrote:
The sneakiest curve ball in this whole game is that we all only get to go around once with a limited number of years to experiment with. No matter how much spectacular progress somebody makes there’s always the question of “yeah, but he never tried X” leaving us with the uncertainty of wondering what could’ve been because nobody can effectively try everything in one lifetime.

[/quote]

Sure, but if someone trained like that they would be a neurotic mess. To always carry around in the back of one’s mind that they are likely missing the perfect program or this or that technique etc would be torturous.

In the midst of all this analysis it is all pointless if the bar is not approached with a spirited enthusiasm, that dares to engage an intimidating weight, to break a sweat even. I realize this discussion would not dispute that, but all the effort attempting to define what optimizes hypertrophy in quantifiable terms I think is actually secondary to unquantifiable attributes.

Tim_Henriques · June 23, 2007, 3:45am

Another source stating that fatigue is key to recruiting additional motor units.

Comes from this site, is long so am only copying the key parts

An example of this principle (the size principle) should suffice to illustrate how it works in the weight room.

If you are benching a weight that is moving at the rate of one repetition per second the initial motor unit muscle fibers will have varying degrees of endurance. Some will be able to go one second before fatiguing whereas others may last up to sixty seconds before dropping off.

If you lifted this weight one time, and it took one second to do it, the motor unit fibers that would be fatigued are those having a low fatigue tolerance of one second, these are the smallest fibers. These would be the solitary motor unit fibers being trained in this exercise. The others did not participate because they weren?t recruited.

Continuing to lift for ten reps larger motor unit fibers would be recruited to keep the weight moving up and down. At this point the fibers with lower fatigue endurance capabilities are unable to develop enough tension to count and have dropped out of the mix.

A larger and greater number of motor unit fibers have been recruited to finish the exercise. These newest recruited fibers are fast and non resistant to fatigue; having an endurance level at fourteen seconds implies that this exercise is nearing conclusion. However, if the exercise stops at twelve reps the latest motor unit fibers were not fatigued.

By Danny M. O?Dell, MA. CSCS*D

Scotacus · June 23, 2007, 3:49am

[quote]Sentoguy wrote:
Socrates,

If you have found out what works well for you and has been giving you results then I applaud you. Keep up the good work.

I personally am not trying to tell anyone here how to train. If someone wants to train to failure and has found that doing so gives them good results, then more power to them.

As I’ve stated several times before, my OP was simply an attempt to define the size principle and how it is believed to relate to MU recruitment. So far I feel that I’ve managed to illustrate that force (weight) is the one factor in MU recruitment that cannot be ruled out.

I have also illustrated that failure occurs in many situations where it doesn’t affect MU recruitment. Therefor, failure/fatigue cannot be considered to govern MU recruitment. Once again, not saying that it doesn’t have it’s benefits though.

Good training,

Sentoguy[/quote]

I never got the sense you were preaching, your posts throughout this forum are always well thought out and articulated. Enjoy your discussion, and ignore the nay-sayers like me!

Majin · June 23, 2007, 4:17am

[quote]Tim Henriques wrote:
Another source stating that fatigue is key to recruiting additional motor units.

Comes from this site, is long so am only copying the key parts

[/quote]

This isn’t a study but a guy writing a breakdown of when you begin lifting an unknown weight at an unknown speed and not “trying to lift a heavy weight as fast as possible”.

All studies that I’ve read(and the initial Hobberman papers) describe the recruitment pattern, yes. But not lifting a heavy weight as fast as possible.

The more units you recruit, the faster you can move the weight, period. Therefore the repetitions in which you are strongest are the ones recruiting all your fibers! What is so difficult?

buffalokilla · June 23, 2007, 4:53am

The entire exchange between Tim and Sento hinges on this:

Tim is discussing fiber recruitment over the course of an entire set and mistakenly discussing the size principle in this context.

Sento is correcting this mistake with a lot of words. Well, but many words. You don’t happen to be a Penn State guy do you?

Also, in general, EMG has been fairly poorly discussed in this thread. Higher EMG != more force production or fiber contraction all the time. EMG will be higher at the end of a many rep set but force production won’t be higher. Consider the implications, I’m going to bed.

Majin · June 23, 2007, 5:38am

[quote]buffalokilla wrote:
The entire exchange between Tim and Sento hinges on this:

Tim is discussing fiber recruitment over the course of an entire set and mistakenly discussing the size principle in this context.[/quote]

The size principle IS in this context because the point Waterbury’s article made was that the last all out reps do not involve any additional muscle fibers.

Tim argues that you do. But he misses the point of the article: “Speed is positively correlated with force. To get the highest speed, you need the highest force. To get the highest force, you must recruit as many motor units as possible. There’s absolutely no way you can lift a barbell faster by recruiting fewer motor units. Moreover, the faster a barbell is moving, the more motor units you’re recruiting.”

In the studies Tim reads a moderate weight is being lifted with moderate effort until exhaustion, almost giving the fibers an endurance test.Such a set does not require the fastest motor units to be involved until all the more endurable ones give out.

But by the article an effort is made to lift a weight AS FAST AS POSSIBLE from rep 1. You give your maximum force output from the first repetition. Therefore your your fastest repetitions will be the ones involving all the units and as you slow down the numbers will only drop because the fastest MUs would be the first to give.

It’s like you’re isolating the fast motor units because you engage all the units simultaneously which allows the fast ones to burn out FIRST. This is also why every big lifter I’ve ever seen lifts fast.

So although Tim, no doubt, understands the size principle correctly, he is not applying the technique pointed out in the article of using all your force AT ONCE, and NOT as needed.

Hope that clears it up for both of them.

JDK · June 23, 2007, 8:14am

[quote]Majin wrote:
But by the article an effort is made to lift a weight AS FAST AS POSSIBLE from rep 1. You give your maximum force output from the first repetition. Therefore your your fastest repetitions will be the ones involving all the units and as you slow down the numbers will only drop because the fastest MUs would be the first to give.

It’s like you’re isolating the fast motor units because you engage all the units simultaneously which allows the fast ones to burn out FIRST. This is also why every big lifter I’ve ever seen lifts fast.

So although Tim, no doubt, understands the size principle correctly, he is not applying the technique pointed out in the article of using all your force AT ONCE, and NOT as needed.

Hope that clears it up for both of them.[/quote]

Majin, I totally agree with you here. I’ve started training like this now - going all out from the first rep - but stopping as soon as I feel fatigue will slow me down noticeably. Thing is, when going all out, I noticed that failure wasn’t very far from slowing down (when I did go a bit over)!

I tried this out last night, very short rest periods and higher sets than usual. By the end of the workout I was floored (trained for an hour, longer than usual, but hit chest, back and legs). But after an hour I felt great. This morning I feel fine and will hit the gym again.

I’m sure a lot of the big guys already train like this. But putting it into words helps the rest of us. Even if you had to see someone train like this, you may not get it that going all out from rep 1 and just when fatigue sets in is a major factor.

Tiribulus · June 23, 2007, 12:09pm

[quote]Scotacus wrote:
Tiribulus wrote:
The sneakiest curve ball in this whole game is that we all only get to go around once with a limited number of years to experiment with. No matter how much spectacular progress somebody makes there’s always the question of “yeah, but he never tried X” leaving us with the uncertainty of wondering what could’ve been because nobody can effectively try everything in one lifetime.

Sure, but if someone trained like that they would be a neurotic mess. To always carry around in the back of one’s mind that they are likely missing the perfect program or this or that technique etc would be torturous.

In the midst of all this analysis it is all pointless if the bar is not approached with a spirited enthusiasm, that dares to engage an intimidating weight, to break a sweat even. I realize this discussion would not dispute that, but all the effort attempting to define what optimizes hypertrophy in quantifiable terms I think is actually secondary to unquantifiable attributes. [/quote]

The point I was making was, how to do you verify stuff like this? By “like this” I mean training theories generally. Statistical probability would appear to reign supreme at this point. The higher the number of people who demonstrate success within a given set of parameters the more reliable the claims of superiority.

I’d like to think I was blessed through no credit to myself with a level of intelligence that sneaks into the above average range somewhere and I have no problem wading through the high science. At one time nothing thrilled me more. Somewhere along the way I burned out on all the dizzying scholarship. Now it’s mainly “lemme know how many guys do well with this”.

Tim_Henriques · June 23, 2007, 12:27pm

[quote]Majin wrote:
So although Tim, no doubt, understands the size principle correctly, he is not applying the technique pointed out in the article of using all your force AT ONCE, and NOT as needed.

Hope that clears it up for both of them.[/quote]

Majin and I are actually closer in thought than I initially guessed. I agree that the faster you lift, you recruit more Type II MU’s in the beginning. I still feel that continuing to try to lift as fast as possible, even if the rep speed will slow down a bit, will recruit further untapped fast MU’s as the body fatigues, but other fast MU’s that the body was using on the first couple of reps will fatigue and drop out.

So at the end of the set you are recruiting less overall motor units thereby making it harder (and slower) but you have hit a higher percentage of the overall muscle than if you stopped before you slowed down in rep speed. I think my initial chart shows this pretty well (the gray bar is bigger on the first rep than the last, meaning more of the muscle is currently working).

Take it easy,
Tim

Majin · June 23, 2007, 2:37pm

[quote]Tim Henriques wrote:
I still feel that continuing to try to lift as fast as possible, even if the rep speed will slow down a bit, will recruit further untapped fast MU’s[/quote]

Find me a study where it says that MAXIMAL effort with a heavy weight leaves out some fast motor units in the basket.

Do you realize that your nervous system recruits MUs as required? It means that if you’re lifting a pencil your fast motor units will not get recruited until you’ve done many hundreds of reps. But if you’re lifting a 1RM ALL of your MUs are utilized almost instantly.

SHOW ME ONE STUDY TO SUPPORT YOUR CLAIM.

You’re misreading your own graph. Now I just think you’re lying. The gray bar is bigger in the LAST reps, not the first. It’s bigger because it’s closer to 100%, unless you really don’t know how to read graphs.

And again, your graph is not applied to a maximal effort set. It shows someone lifting a 14RM at moderate speed for 10 reps. When you do that the table is absolutely correct.

But in our example there’s no way the first three reps can be so easy as to only recruit HALF of the fibers. What were you thinking? 30% of 1RM?

I don’t believe you’re telling the truth anymore. Looks like you’re just trying to weasel out of this. Get over it already.

W114 · June 23, 2007, 8:07pm

[quote]Majin wrote:
Find me a study where it says that MAXIMAL effort with a heavy weight leaves out some fast motor units in the basket.[/quote]

Why don’t you ask the experts themselves about this one?

Ever expert I’ve ever read about stated that NO ONE uses all of their available ‘fast motor units’ at once. Top level lifters with years and years of experience may use up to 90% of available muscle fibers during a quick/speed lift/movement. Novice lifters use maybe 50% of their available muscle fibers at best.

Through proper training, novice lifters become more efficient at a lift and start recruiting progressively more and more muscle fibers in simultaneous conjunction.

Again I repeat…ask the experts themselves. Ask CW, CT, Alwyn, Tate, Simmons, anyone else that knows what they’re doing…NO ONE uses all of their ‘fast motor units’ at the same time. Not even the elite of the elite.

tpa · June 23, 2007, 9:48pm

Just posted by Thib in his locker:

[quote]
"Furthermore in some cases you WANT to train in a state of incomplete recovery. When training for muscle growth for example. Incomplete rest leads to a higher level of lactate thus to a higher level of growth hormone production. Incomplete rest also forces your body to use more and more motor-units to do the job. HOWEVER incomplete rest decrease your force potential…

So when training for strength you should shoot for complete recovery… without losing the potentiation effect. But when training for size then you can use the incomplete rest method."[/quote]

http://www.T-Nation.com/readTopic.do?id=1149303&pageNo=126#bottom

I completely agree that CW’s recommendations are great for strength gains. This has been proven in the trenches by athletes, powerlifters, and olympic lifters. But I don’t think it is the best way to train for hypertrophy.

Perhaps it could be applied during a training cycle to increase strength. It could also allow you to lift a greater volume of weight throughout your workout before you’re completely exhausted which could also be beneficial (I think this is the point that CW is getting at).

But to maximize muscle SIZE, I think you need to train in a fatigued state…which means bar speed will decrease.

JDK · June 23, 2007, 10:10pm

[quote]tpa wrote:
But to maximize muscle SIZE, I think you need to train in a fatigued state…which means bar speed will decrease.[/quote]

The impression I got was that you’d rest less between sets. Doesn’t mean that you keep going after the bar starts to slow - that’s a separate factor.

Majin · June 24, 2007, 2:47am

[quote]W@LRUS!1 wrote:
NO ONE uses all of their ‘fast motor units’ at the same time. Not even the elite of the elite.[/quote]

We’re talking about all fast units that you are able to recruit in that exercise, not all the fast units in the entire muscle-group. For different people it will be a different number but what remains is that they cannot recruit any more doing that exercise.

W114 · June 24, 2007, 3:51am

[quote]Majin wrote:
W@LRUS!1 wrote:
NO ONE uses all of their ‘fast motor units’ at the same time. Not even the elite of the elite.

We’re talking about all fast units that you are able to recruit in that exercise, not all the fast units in the entire muscle-group. For different people it will be a different number but what remains is that they cannot recruit any more doing that exercise.[/quote]

I’ll attempt to explain the reasoning behind using the repetition method…

A novice lifter uses 40% (because his CNS is not very efficient) of his fast twitch fibers during the first three reps of a squat, these first three reps are easy.

Those fast twitch fibers fatigue but he keeps attempting more reps. His body throws another 30% (previously unused) fast twitch fibers at the job and those fatigue during the next three reps, these three reps are more difficult.

Although the previous three reps were difficult he carries on and attempts more reps. So his body throws another 20% (previously unused) fast twitch muscle fibers at the task. He barely gets two more reps out, racks the weight and falls back in utter exhaustion.

During the course of this set he recruited 90% of his available fast twitch muscle fibers. If he had quit right after the easy reps he would of never tapped into those extra fast twitch muscle fibers.

This (simplified version), to my understanding, is the reasoning behind using the repetition method.

Does it work? Is it an effective method for gaining strength?

I don’t have the definitive answer to these questions. But there are millions of bodybuilders, powerlifters, and gym-rats the world over that feel they’ve made good gains from it.

Professor_X · June 24, 2007, 4:08am

[quote]W@LRUS!1 wrote:
Majin wrote:
W@LRUS!1 wrote:
NO ONE uses all of their ‘fast motor units’ at the same time. Not even the elite of the elite.