Waynes own emg studys fast reps = more force/tension on the muscles

[waynelucky2]

Dear all,

Several months back, we had many debates on the force/strength that was used by the muscles, and thus the tension put on them. Some people said the total force output from the muscles were the same in the below fast and slow rep/s, I said the force or muscle activation was far higher in the fast, thus more tension on the muscles. SO AFTER WELL OVER 6 YEARS HERE OF DEBATING AND OVER AT ELLINGTON’S, HOME OF HIT. I DECIDED TO BUY AN EMG MACHINE.

It was like this.

Wight used roughly 80%
Fast, 6 reps at .5/.5 = 6 seconds, or/and 24 reps at .5/.5 = 24 seconds.

Slow, 1 rep at 3/3 = 6 seconds, or/and 4 reps at 3/3 = 24 seconds.

Some thought they could work it out with paper physics, but forgot to add in many variables, I did not.


Got my EMG. I will have to have a very good read first, however, I put {its a dual channel EMG} two pads on my Forearm, and did a very crude test, did very fast wrist curls for the set time, was about 15 seconds, then did very slow wrist curls for the set time, was about 15 seconds.

Fast = average work = 55.3 ?V RMS {root-mean-square}
Slow = average work = 42.2 ?V RMS {root-mean-square}

Pretty much what I or most people would expect.

Will try a few slow and fast leg extensions later tonight.
Get back to you when more detailed studies/tests have been taken.

Wayne

[waynelucky2]

The last post was a few hours ago.

Did a far more scientific test/study just now. Was after a full leg workout. First I did right leg, leg extension, quite fast, something like .5/.5
Then I did left leg, leg extension, quite slow, something like 3/3.
Both obviously were to the set time, which was 25 seconds.

Fast = average work = 295 iV RMS {root-mean-square}
Slow = average work = 177 iV RMS {root-mean-square}

The fast was 118 IV or 61% higher than the slow, as of MORE average/total force/strength is used.
So what have the few that said other have to say about this ???

Yes I will video it next time.

Wayne

[waynelucky2]

The machine takes the average, peak and many other things, will post all when I know more about to use it.

Comments please, and anyone want me to do a test for them, please say.

Wayne

[joerevans]

You are basically confusing the issue. For a set time, there is no doubt that you are going to get more out of fast movement simply because you can get more reps.
I think the debate is more about a per rep rather than Average over set time.
What is the total work for 6 fast reps vs. 6 slow reps or 6 seconds at fast vs. 36 seconds at slow? Why should I chose to do my 20 push-ups at a slow, moderate or fast cadence? After all, I'm only going to do 20 regardless, does it make a difference?

[gomez26]

i always thought the usefulness of emg studies were limited to seeing what regions of the muscle are most worked by a certain exercise. so the readings i believe are useful within a certain exercise (movement pattern) for comparing different regions.

so for example, for triceps having 3 heads, doing overhead rope extensions may give readings of 200 for inner head, 180 for middle head, 120 for outer head; while dips may give 180 for the inner head, 180 for middle head, 180 for outer head. (numbers are just for example).
from this u would conclude what exercise targets what areas the most, but i dont believe u can make conclusions using the magnitudes between exercises i.e. as to which exercise is overall better even for a certain region because the movement pattern is totally different. i remember seeing study results showing that leg extensions were only a few points behind squats for the quads (a difference of like only 5%) which most experienced people would agree is not accurate.

likewise, i dont believe comparing readings for the same exercise using different speeds is accurate, because some of the highest readings you can possibly get are from throwing a relatively light object like a ball - this gives magnitudes even higher than 1 rep maxes using weights. this is my main problem with your comparisons wayne, i believe emg studies are best limited to comparison of regions hit by a certain movement pattern at a certain speed. if anyone has any differing experience with using this equipment it would be great to hear.

[palumboism]

The fast was 118 IV or 61% higher than the slow, as of MORE average/total force/strength is used.
So what have the few that said other have to say about this ???[/b]


Wayne

Hahaha exactly this. More voltage means more muscle activity that's why failure occurs sooner with fast reps. If not why is the voltage higher? Muscles setting offf more voltage just for fun of it? All that tripe about how peaks are cancelled by troughs, lets see dooglis or those other boneheads with all those colourful stupid graphs in the past threads show their faces in this thread & face the music, they will not have the nerve to.

[morderstwo]

Fast = average work = 295 iV RMS {root-mean-square}
Slow = average work = 177 iV RMS {root-mean-square}

The fast was 118 IV or 61% higher than the slow, as of MORE average/total force/strength is used.
So what have the few that said other have to say about this ???[/b]

Wayne, I admire your enthusiasm but you are in over your head.
First you have to learn what root-mean-square is, its clear you think it is some average, or total measure.
It would interest you to know that over one cycle of a sinusoid the average value is zero, while the RMS is 0.707 x the peak magnitudes, regardless positive or negative.
Like we have always told you faster reps mean higher peaks in tension due to acceleration in the first half of the concentric phase that are matched by equal drops in tension due to deceleration in the second half, but the average tension value across the rep is the same - simply the weight on the bar. Higher peaks & lower troughs will mean the RMS goes up, you clearly think the RMS is an average which it is not.

Thanks to the guy who alerted me to this thread (/sarcasm) I will try hard to not waste my time but don't know if I will succeed, as all-pro once said "I am a glutton for punishment", I think that applies to many of us in Wayne's past threads, perhaps a reunion of lunatics, but I guess some interesting discussions do come out of it.

Some thought they could work it out with paper physics, but forgot to add in many variables, I did not.

And which variables might that be?

All that tripe about how peaks are cancelled by troughs, lets see dooglis or those other boneheads with all those colourful stupid graphs in the past threads show their faces in this thread & face the music, they will not have the nerve to.

Strong grasp of RMS

[waynelucky2]

Its IS the Average work, average muscle activity, what do you think it is then ???


Fast = average work = 295 iV Average work, average muscle activity.
Slow = average work = 177 iV Average work, average muscle activity.


http://www.tensmachines.co.uk/NeuroT...ETS_p_154.html


Not sure I put this in right, RMS {root-mean-square} Just coped that from the site, it does NOT give this on the readout.

Wayne

[all pro]

Its IS the Average work, average muscle activity, what do you think it is then ???


Fast = average work = 295 iV Average work, average muscle activity.
Slow = average work = 177 iV Average work, average muscle activity.


http://www.tensmachines.co.uk/NeuroT...ETS_p_154.html


Not sure I put this in right, RMS {root-mean-square} Just coped that from the site, it does NOT give this on the readout.

Wayne

Your 1 rep max would test HIGHER!
You're measuring power not force, strength or work! Speed X strength = power.
Work = load x distance. Time is irrelevant.
Gomez26........I hate you!
I'm outtahere!

[douglis]

Hi Wayne...I won't even comment that you spent 3800 euros to buy an EMG.It's more sad than funny...so I'll try to help you here.

The magnitude you should try to measure is not the RMS but the iEMG.

When you use the RMS you take the squares of the original values....you divide them by the number of the values...and finally you calculate the square root.
If you were taught maths at high school...you should know that the square of a negative value(the deceleration phase for example) is positive.So practically you skip the deceleration phases from your results.

...and of course your result by no means represents the "work".Probably represents the average peak value of force which is obviously greater in fast lifting.

The magnitude you're interested is the iEMG(integrated electromyography) which such an expensive machine must include.
It is found by the area between the EMG curve and the axis of time.It represents the total muscle activation(TMA) for the given time and and if you divide the iEMG by time you have the muscle activation per unit of time.

Just like they did in those studies:

There were significantly greater
MAPT in the slow group. The effect was more prominent for
the biceps brachii (p < 0.01), triceps brachii and posterior
deltoid muscles (p < 0.05). The results showed that greater
muscle activation occurred in the slow push-up speed group.
http://jmbe.bme.ncku.edu.tw/index.ph...ewFile/546/823

at the slow
push-up speed, the total muscle activations in the triceps brachii, biceps brachii, anterior deltoid, pectoralis major, and
posterior deltoid, respectively, were 1.47, 2.43, 1.42, 1.48, and 1.91 times higher than those at the fast push-up speed.
http://jmbe.bme.ncku.edu.tw/index.ph...ewFile/635/839

[mrmrbill]

Is there an appropriately academic answer for the required speed of pull ups for optimal lat growth in the form of a rectilinear equation? I mean like, dude, is the fibre recruitment significantly reduced on the order of 1/2" off my "bat wings gain potential" if my weighted pull ups fall off 0.25 sec./rep at the eccentric portion over 10 reps during a year? Or, perhaps better stated, I'm just curious as to the real world effects of the new machine you bought.

"42" ... required speed.

[douglis]

Here you can uderstand the difference better.
http://www.biopac.com/researchApplic...&AF=61&Level=3

The RMS is formed by the green line and can take only above zero values.In contrast the EMG(red line) goes below zero too.

Enough said...outta here too.Gomez....are you happy now???LOL

[waynelucky2]

Wayne, I admire your enthusiasm but you are in over your head.
First you have to learn what root-mean-square is, its clear you think it is some average, or total measure.
It would interest you to know that over one cycle of a sinusoid the average value is zero, while the RMS is 0.707 x the peak magnitudes, regardless positive or negative.
Like we have always told you faster reps mean higher peaks in tension due to acceleration in the first half of the concentric phase that are matched by equal drops in tension due to deceleration in the second half, but the average tension value across the rep is the same - simply the weight on the bar. Higher peaks & lower troughs will mean the RMS goes up, you clearly think the RMS is an average which it is not.

Thanks to the guy who alerted me to this thread (/sarcasm) I will try hard to not waste my time but don't know if I will succeed, as all-pro once said "I am a glutton for punishment", I think that applies to many of us in Wayne's past threads, perhaps a reunion of lunatics, but I guess some interesting discussions do come out of it.



And which variables might that be?



Strong grasp of RMS

Not much time now. Will get back to you in full.The EMG will take the reading of work, as in muscle activity for the given time. And the first reading it gives is average, meaning the average muscle activity is higher, meaning the totally activity is higher. What do you think EMG does then ???

How could anyone think that if I moved a weight 6m to your 2m in the same time span, that the person moving the load 2m would use the same force/strength, or have the same muscle activity, please just tell me how ???

Even if we take 40% off for my deceleration {but I am still using force/strength then} I have still moved the weight 3.6m in the same time span as you have only moved the weight 2m, and we have yet to take your deceleration off. Don’t people understand you need more force/strength for faster accelerations ???

Wayne

[waynelucky2]

Here you can uderstand the difference better.
http://www.biopac.com/researchApplic...&AF=61&Level=3

The RMS is formed by the green line and can take only above zero values.In contrast the EMG(red line) goes below zero too.

Enough said...outta here too.Gomez....are you happy now???LOL

Well thats what I am using a EMG, as you say; In contrast the EMG (red line) goes below zero too. Mine fast would go below zero, thus making it worst for my readout.But it does work like that.

I CAN BELIVE THIS, I TAKE TROUBLE TO BUY A EMG, AND YOU STILL SAY NOW THAT A EMG IS WRONG, ROL.

Wayne

[waynelucky2]

Hi Wayne...I won't even comment that you spent 3800 euros to buy an EMG.It's more sad than funny...so I'll try to help you here.

The magnitude you should try to measure is not the RMS but the iEMG.

I did not spend 3800, I was teasing, you can see the price on the page.

I did, read what the machine says. The emg is the first it gives out.

When you use the RMS you take the squares of the original values....you divide them by the number of the values...and finally you calculate the square root.
If you were taught maths at high school...you should know that the square of a negative value(the deceleration phase for example) is positive.So practically you skip the deceleration phases from your results.

...and of course your result by no means represents the "work".Probably represents the average peak value of force which is obviously greater in fast lifting.

The magnitude you're interested is the iEMG(integrated electromyography) which such an expensive machine must include.

Thats what its reading.

It is found by the area between the EMG curve and the axis of time.It represents the total muscle activation(TMA) for the given time and and if you divide the iEMG by time you have the muscle activation per unit of time.

Just like they did in those studies:

There were significantly greater
MAPT in the slow group. The effect was more prominent for
the biceps brachii (p < 0.01), triceps brachii and posterior
deltoid muscles (p < 0.05). The results showed that greater
muscle activation occurred in the slow push-up speed group.
http://jmbe.bme.ncku.edu.tw/index.ph...ewFile/546/823

at the slow
push-up speed, the total muscle activations in the triceps brachii, biceps brachii, anterior deltoid, pectoralis major, and
posterior deltoid, respectively, were 1.47, 2.43, 1.42, 1.48, and 1.91 times higher than those at the fast push-up speed.
http://jmbe.bme.ncku.edu.tw/index.ph...ewFile/635/839

Here is the manual.

Hi,The output on the American transformer for the Davicon is 12VAC 500mA. It gives a very simple visual and digital readout from 2 channels. In my opinion, the Neurotrac ETS (also dual channel) is much more comprehensive and better suited to the experiments you wish to perform. The neurotrac is designed for gathering average statistics over work and rest periods for clinical trails as you can see from the manual:http://www.win-health.com/files/wpro...rotrac-ets.pdf It also has many other benefits over the Davicon, including the ability to provide electrical stimulation.Hope this helps,

Wayne

[waynelucky2]

Hi All-pro.

I am measuring the muscle activity by EMG, the more muscle activity the more a higher EMG reading.

Wayne

[mrmrbill]

[b]I CAN BELIVE THIS, I TAKE TROUBLE TO BUY A EMG, AND YOU STILL SAY NOW THAT A EMG IS WRONG, ROL.[b]

Wayne

One o' my ex-GF had me take out a mis-grown tree in her yard with a pick-axe. Turned out, I was using the pick-axe wrong and she had to give me instructions -- which worked! We got the tree out, finally. EMG readings aren't much just because you bought it and are using it. It kinda matters more if it's being used correctly as an EMG. Now about that fibre recruitment for weighted pullups with descending speed over force quantity, how did we work out on that, with regard to latissimus dorsi width? 42?

[all pro]

Hi All-pro.

I am measuring the muscle activity by EMG, the more muscle activity the more a higher EMG reading.

Wayne

It doesn't mean more muscle activity. It means more CNS activity. The fastest rep speed will result in fewer fibers contracting. We've had this discussion before. By the time the slower fibers begin to contract the rep is over. The net result is LESS total force. The 2x fibers contract maximally,most of the 2Ds contract, some of the 2Cs contract, good luck with the 2As. The maximum force out put occurs with a 1-3 rep max when bar speed is near ZERO! After that maximum force out put drops regardless of bar speed but maximum power will increase all the way down to about 60-70% of 1 RM at maximum contraction speed.

[douglis]

Well thats what I am using a EMG, as you say; In contrast the EMG (red line) goes below zero too. Mine fast would go below zero, thus making it worst for my readout.But it does work like that.

Yes...but you convert it to RMS.

I CAN BELIVE THIS, I TAKE TROUBLE TO BUY A EMG, AND YOU STILL SAY NOW THAT A EMG IS WRONG, ROL.

Wayne

I just tried to help but it doesn't seem to worth.Contact with those who sold you the machine...good luck.

[SumDumGoi]

Your 1 rep max would test HIGHER!
You're measuring power not force, strength or work! Speed X strength = power.
Work = load x distance. Time is irrelevant.
Gomez26........I hate you!
I'm outtahere!

This! If you are looking to see if faster reps produce higher "forces" all you need to look at is muscular force produced, or your 1RM. Go to the gym and see where you are able to move the greatest amount of weight, using fast or slower reps. You need to stop confusing Power and Force.

[waynelucky2]

This! If you are looking to see if faster reps produce higher "forces" all you need to look at is muscular force produced, or your 1RM. Go to the gym and see where you are able to move the greatest amount of weight, using fast or slower reps. You need to stop confusing Power and Force.

Well said and a big thx.

We use the same load, same time, but diffrent speeds, thus the fast gets more disstance, how can anyone even thick/think, you can move the same load in the same time span with out using more total force in behond me. And with this thay add it up to averages and forget the rest !!!

Wayne

[waynelucky2]

Hi all, and thx for all the replies, no time tonight going out, PLEASE I need things explained.

I do not get what you mean by, that you should have the negative values also ???

{the machine reads, Passive and Active phases: EMG and NMS in one programme.
Dual channel EMG (Biofeedback)
Manual and Automatic threshold control.
EMG Biofeedback between stimulation (muscle activity and tiredness indication when using. Meaning it reads all the muscle activity, yes or no ???}

D. thought or said about this before on force and on energy, don’t get why he thinks this.

I lift a 80 pound weight up, my 80%, I use 100 pounds of force/strength for the first 60% of the ROM, then, use say 75 pound of force/strength for the deceleration, meaning I am using force all the time until the milly second of the transition from positive to negative, then I use a force to lower the weight. So what is he on about the negative forces ??? When I use any force/strength, it’s been used, and CAN NOT be given back, yes or no ??? If you think like D. that somehow it’s given back, please say why and how.

Let’s say I was cleaning 80% and I lift the weight with my force/strength for ??? 1m, then as of the acceleration, if I used not force/strength at all, the weight would carry on for 25mm, I have still used the force/strength to lift the weight 1m, you can’t take that force/strength away from me, you can take from the 25mm the negative portion and take it away from the 1m positive force/strength portion of the lift, can you ??? THAT’S WHY IF YOU’RE THINKING LIKE THIS, IT’S WHERE PAPER PHYSICS IS WRONG.

If you not on about that, what are you on about ??? Please explain. As I said above, I lift a weight and the machine measures all muscle force/strength activity, I then lower the weight, the machine measures all the muscle force/strength activity, and does this for the set time, and then give a readout, it does exactly the same on the slow rep.

There are four pads, and I placed them all over my quads.

Root Mean Square EMG (RMS EMG) is defined as the time windowed RMS value of the raw EMG. RMS is one of a number of methods used to produce waveforms that are more easily analyzable than the noisy raw EMG.

So what do you think the difference is ??? It’s the same as raw.

Some people are saying they are out of here, cos they were wrong, it you think your not, please lets just have a grown up debate, as I did take the trouble of buying a EMG.

I THINK THE BELOW SUMS UP I AM RIGHT.

http://jrnlappliedresearch.com/artic...Iss1Fukuda.pdf

Wayne

[SumDumGoi]

By moving the weight faster does not mean you are going to create more force. Certainly you would be increasing muscular activity as you increase the recruitment of higher threshold motor units as you recruit more muscle fibers. This is what you have shown with you EMG. However, what your EMG data does not provide you with is a measurement of muscular "force". As you increase the velocity of the contraction you decrease the number of actin-myosin cross-bridges that are formed at any given time. Despite that there are now a decreased total number of actin-myosin cross-bridges formed at any given point in time you are increasing their cycling rate (how quickly they detach and reattach), which needs to occur due to the increase in velocity.

If you were to measure the force produced within the muscle (and not the muscular activity measured using EMG) you would find that as the velocity increases, the force you produced is decreased. This is a very basic principle that is taught in any exercise physiology class. If your results are somehow different from what is found inside of a physiology textbook perhaps you should aim to publish your findings.

[morderstwo]

You're measuring power not force, strength or work! Speed X strength = power.

Fast = average work = 295 iV Average work, average muscle activity.
Slow = average work = 177 iV Average work, average muscle activity.

Yes it appears to be power given that most likely iV signifies currentxvoltage which is the electrical equivalent of power.

By moving the weight faster does not mean you are going to create more force. Certainly you would be increasing muscular activity as you increase the recruitment of higher threshold motor units as you recruit more muscle fibers. This is what you have shown with you EMG. However, what your EMG data does not provide you with is a measurement of muscular "force". As you increase the velocity of the contraction you decrease the number of actin-myosin cross-bridges that are formed at any given time. Despite that there are now a decreased total number of actin-myosin cross-bridges formed at any given point in time you are increasing their cycling rate (how quickly they detach and reattach), which needs to occur due to the increase in velocity.

If you were to measure the force produced within the muscle (and not the muscular activity measured using EMG) you would find that as the velocity increases, the force you produced is decreased. This is a very basic principle that is taught in any exercise physiology class. If your results are somehow different from what is found inside of a physiology textbook perhaps you should aim to publish your findings.

Repping a weight faster does produce higher peak forces. This does not contradict the Force-Velocity curve. This curve describes the situation at any given point in time, in other words instantaneous force. When you lift weights for many reps you have to stop & reverse direction each half-rep, so this motion is not continuously high speed. The force on the muscles during high speed reps are the highest at the turning point from eccentric to concentric. Since the direction is reversing the instantaneous velocity is zero by definition, this corresponds to maximal force as per the Force-Velocity curve (not absolute maximal that the muscle is capable of, but maximal for that particular weight). Then, during the upstroke, as velocity builds up the tension obviously drops as per curve. So during fast repetitions you are continuously moving up & down the force-velocity curve, not simply remaining in one spot. Like I said this curve describes the situation at any given point in time.

Acceleration (extra force) is maximal when velocity is zero and velocity is maximal when acceleration is zero. So none of this contradicts the curve. Velocity simply lags acceleration, in other words they are out of phase with each other similar to a mass on a spring system. The more velocity that was built up half way down the eccentric, the greater the force that will be required for direction reversal due to the momentum.

So repping a weight faster leads to higher instantaneous peak forces but also lower instantaneous trough forces. The average forces remain the same because the trough cancels the peak across the whole rep. The only way to increase average force is to use a greater weight. Of course Wayne does not understand this, he thinks the average force goes up simply by using a higher speed with a given weight. The fluctuations will obviously be detected by the emg, but Wayne is using RMS which does not take into account troughs cancelling peaks, thats why he thinks the average has gone up.

I THINK THE BELOW SUMS UP I AM RIGHT.
http://jrnlappliedresearch.com/artic...Iss1Fukuda.pdf
Wayne

This is out of context. RMS is perfectly valid to use in this case because they are comparing isometric contractions with varying loads. Isometric contractions don't fluctuate in tension. Repping a given weight very fast creates wild fluctuations, RMS cannot be used to compare different speed reps using the same weight.

[Farley1324]

Yes it appears to be power given that most likely iV signifies currentxvoltage which is the electrical equivalent of power.






Repping a weight faster does produce higher peak forces. This does not contradict the Force-Velocity curve. This curve describes the situation at any given point in time, in other words instantaneous force. When you lift weights for many reps you have to stop & reverse direction each half-rep, so this motion is not continuous high speed. The force on the muscles during high speed reps are maximal at the turning point from eccentric to concentric. Since the direction is reversing the instantaneous velocity is zero by definition, this corresponds to maximal force as per the Force-Velocity curve. Then, during the upstroke, as velocity builds up the tension obviously drops as per curve. Acceleration (extra force) is maximal when velocity is zero and velocity is maximal when acceleration is zero. So none of this contradicts the curve. Velocity simply lags acceleration, in other words they are out of phase with each other similar to a mass on a spring system.

So repping a weight faster leads to higher instantaneous peak forces but also lower instantaneous trough forces. The average forces remain the same because the peak cancels the trough. The only way to increase average force is to use a greater weight. Of course Wayne does not understand this, he thinks the average force goes up simply by using a higher speed with a given weight.

csb?

[all pro]

Yes it appears to be power given that most likely iV signifies currentxvoltage which is the electrical equivalent of power.






Repping a weight faster does produce higher peak forces. This does not contradict the Force-Velocity curve. This curve describes the situation at any given point in time, in other words instantaneous force. When you lift weights for many reps you have to stop & reverse direction each half-rep, so this motion is not continuously high speed. The force on the muscles during high speed reps are the highest at the turning point from eccentric to concentric. Since the direction is reversing the instantaneous velocity is zero by definition, this corresponds to maximal force as per the Force-Velocity curve (not absolute maximal that the muscle is capable of, but maximal for that particular weight). Then, during the upstroke, as velocity builds up the tension obviously drops as per curve. So during fast repetitions you are continuously moving up & down the force-velocity curve, not simply remaining in one spot. Like I said this curve describes the situation at any given point in time.

Acceleration (extra force) is maximal when velocity is zero and velocity is maximal when acceleration is zero. So none of this contradicts the curve. Velocity simply lags acceleration, in other words they are out of phase with each other similar to a mass on a spring system. The more velocity that was built up half way down the eccentric, the greater the force that will be required for direction reversal due to the momentum.

So repping a weight faster leads to higher instantaneous peak forces but also lower instantaneous trough forces. The average forces remain the same because the trough cancels the peak across the whole rep. The only way to increase average force is to use a greater weight. Of course Wayne does not understand this, he thinks the average force goes up simply by using a higher speed with a given weight. The fluctuations will obviously be detected by the emg, but Wayne is using RMS which does not take into account troughs cancelling peaks, thats why he thinks the average has gone up.



This is out of context. RMS is perfectly valid to use in this case because they are comparing isometric contractions with varying loads. Isometric contractions don't fluctuate in tension. Repping a given weight very fast creates wild fluctuations, RMS cannot be used to compare different speed reps using the same weight.

This has been tested to death.......and beyond. Faster rep speeds DO NOT produce higher peak force. They produce LOWER peak force. The reason is a reduction in cross bridging. There isn't enough time for the slower fast twitch fibers to cross bridge. The result is less peak force produce by the muscles. You can lift more weight through the combination of fast contraction speed and the rapid reversal of direction. But using the stretch/shortening cycle doesn't mean that the muscles have produced higher peak force. All it means is that you've used your joints ligaments and tendons like rubber bands. The highest peak forces recorded will always happen at 85+ percent of a 1 rep max. 50-70% produces the highest peak power. Lou Simmons of West Side has used force plates to measure all of this. Wayne is aware of all of this and chooses to continue to purposely confuse force and power to push his agenda.
So to sum it up, faster MOVEMENT speeds do not produce higher peak force. Faster contraction speeds with at least 85% of a 1 rep max on the bar produce the highest peak force.
Faster movement speeds with 50-70% of a 1 rep max on the bar produce maximum power.
And finally, fastest turn around speeds produce the fastest path to torn muscles, torn tendons and joint damage.

[douglis]

Yes it appears to be power given that most likely iV signifies currentxvoltage which is the electrical equivalent of power.

Yes...that's what I also believe.The integrated RMS divided by time represents the average power.

Repping a weight faster does produce higher peak forces. This does not contradict the Force-Velocity curve. This curve describes the situation at any given point in time, in other words instantaneous force. When you lift weights for many reps you have to stop & reverse direction each half-rep, so this motion is not continuously high speed. The force on the muscles during high speed reps are the highest at the turning point from eccentric to concentric. Since the direction is reversing the instantaneous velocity is zero by definition, this corresponds to maximal force as per the Force-Velocity curve (not absolute maximal that the muscle is capable of, but maximal for that particular weight). Then, during the upstroke, as velocity builds up the tension obviously drops as per curve. So during fast repetitions you are continuously moving up & down the force-velocity curve, not simply remaining in one spot. Like I said this curve describes the situation at any given point in time.

That's also very true.The maximum force is exerted at the transition point(from negative to positive) where the velocity and acceleration is zero.

[morderstwo]

Faster rep speeds DO NOT produce higher peak force. They produce LOWER peak force.
....
....
The highest peak forces recorded will always happen at 85+ percent of a 1 rep max. 50-70% produces the highest peak power.
....
So to sum it up, faster MOVEMENT speeds do not produce higher peak force. Faster contraction speeds with at least 85% of a 1 rep max on the bar produce the highest peak force.
Faster movement speeds with 50-70% of a 1 rep max on the bar produce maximum power.

We are not talking about the same thing.
I'm not arguing that using a lower weight can produce higher peak forces than using a higher weight.
I'm saying that while using the same weight, faster reps will produce higher peak forces compared to slow reps.

If you lifted 85% of 1RM slowly you will not be able to generate the absolute maximum peak force equivalent to 100% of 1RM. You have to lift 85% as fast as possible this is exactly my point, so you basically agree with me, but this specific misunderstanding has been going on between all of us regarding the Force-velocity curve ever since we first started discussing it over a year ago.

This is why I edited my earlier post to include (in bold)

Since the direction is reversing the instantaneous velocity is zero by definition, this corresponds to maximal force as per the Force-Velocity curve (not absolute maximal that the muscle is capable of, but maximal for that particular weight).

Absolute maximal force the muscle is capable of producing is by using 100% of 1RM or upwards of 85% as long as its fast as possible.

The maximum tension that can be reached using lighter loads will obviously be less than the absolute, my point was that using for example 70% will produce higher peak tensions using fast reps compared to using 70% for slow reps and these peaks will occur at the transition from neg to pos.

That's also very true.The maximum force is exerted at the transition point(from negative to positive) where the velocity and acceleration is zero.

Actually no, acceleration is maximum when velocity is zero. Check out the curves for a reciprocating system.
system. http://forum.bodybuilding.com/attach...3&d=1321180321

[douglis]

Actually no, acceleration is maximum when velocity is zero. Check out the curves for a reciprocating system.
system. http://s65.photobucket.com/albums/h2...¤t=techni9.jpg Velocity lags acceleration by 90-deg.

Yes...my mistake.Acceleration is maximum at the transition point(where velocity is zero)....and the velocity is maximum when the acceleration is zero.The velocity starts to decrease when the acceleration becomes negative(less force than the load is applied).

[Kelei]

Not this **** again...........Wayne buying an EMG is priceless though.

1. Lift as fast as possible.
2. Lower at half of your lift speed.
3. Stop overthinking things.