Question about power / strength relationship

[adamanderson]

Dear Coach,

or whomever has an answer,

Stronger (than one is currently) is always better, is the mantra. Higher force production ability i.e. strength, means higher work capacity. That's very direct and clear. Also, worrying about getting "too strong" is a stupid concern, I get that.

My question however is about how power works, how it relates to things like sprint speed and jumping ability, and how that in turn relates to the concept of diminishing returns:

Strength is, as we all know, the ability to generate force. Power is the measurement of how much force one can generate per a unit of time. Everyone of a given height and frame obviously has a different genetic limit to how strong they can get, and the difference between individuals' genetic limits for power varies so much more.

If I've understood it correctly, the genetic limit for power works as thus: x N/s. So, someone's genetic power capacity may be 500N/s. If this is indeed the case, wouldn't it follow that if one has the strength i.e. force production ability of 500N, that after this point, strength CANNOT be translated to power, meaning that you can now produce 500N of force, and therefore have maxed out your 500N/s power capacity, and that improving your strength to 800N, would still leave your power at 500N/s? ... this of course doesn't specify muscle groups etc, but you get the point.

Now, if that's how it works, wouldn't a person's vertical jump peak at the point where his strength is just enough to meet his genetic power limit? The reason for my inferring that is that, increasing strength after that point, wouldn't increase the force produced during the time that it takes to push off and leave the ground, and, because increasing strength after that point would add mass. So ... the force with which one's body is launched (power) remains the same, while body mass is increased. Same power, more weight. So yeah, given a certain power, the only variable that can be manipulated is weight, and that should be kept as low as possible.

My conclusion based on my premises seems obviously valid, while I concede that I may have missed whatever in my assumptions. If the premises are true however, that peaking in vertical jump ability would also apply to high jump, long jump, throwing, sprinting, etc.

One thing I might've gotten wrong, is that maybe the genetic limit for power doesn't work like that, but instead the genetic limit for force/time (power) is a percentage of a person's strength?! In that case, there would of course be no point of diminishing returns with respect to e.g. the vertical jump ... theoretically that is, ignoring practice, time investment etc.

Also, as a quick aside, I'm pretty sure that I've seen you, Mark, recommend that people competing in powerlifting, should do so at the weight class where they're at their strongest. Are you referring to the weight class where their strength/weight ratio peaks, or at their strongest in an absolute sense? I mean, if the former differs from the latter, shouldn't the former be their optimal weight class?

Thanks!

Regards

[Mark Rippetoe]

The equation for Power is P = (F x d)/t, where F is force applied to the system, d is the distance over which the force is applied, and t is the time over which the force is applied. So in this case, F is strength, d is determined by the test, and t is your explosive ability -- the ability to display strength quickly. The "genetic limit for power" you refer to is determined by the ability to recruit muscle mass into contraction, and is indeed a pretty hard limit that is minimally trainable. Force production is quite trainable for many years. We can take a talented kid with a 36" SVJ who squats 275 and train him up to a 500 without having to resort to exotic means. But if we do this, what happens to his SVJ?

Not much, really. The SVJ is a test of the ability to recruit motor units into contraction rapidly, and that's all it shows us. The SVJ is a measure of your ability to generate enough force within the time it takes to perform the concentric phase of a jump, to accelerate your body's mass upward to impart sufficient velocity and therefore sufficient momentum to it, that it continues upward after the force production between your feet and the ground has stopped. The distance upward is a direct measurement of the force produced in the .25 seconds the contraction takes place, and this is more dependent on how quickly motor units are recruited than the force of the recruitment, since your body's mass is not very heavy. The bottleneck is the ability to "fire" as much of the contractile machinery in the .25 seconds, and for various reasons this is 1.) controlled by genetic endowment and is 2.) not very trainable.

It is interesting that a kid with a 36" SVJ is always stronger untrained than a kid with an 18" SVJ untrained, since the big SVJ is recruiting more muscle mass into contraction than the little SVJ. But the 36" kid is just as trainable for F as the 18" kid, and not getting him stronger is a huge mistake.

When we take the kid from 275 to 500, the algebra shows us that his P goes up, even though this does not affect his SVJ proportionally -- doubling his squat does not double his SVJ, no way, not even close. This is due to the fact that the SVJ does not depend on max force production, because you're only jumping against your bodyweight. A true 1RM force production event only occurs under a 1RM load, which is not an instantaneous power display but rather a summation event. And this time constraint is why the clean is much more influenced by an increase in strength, because it takes maybe 5-6 times as long as the SVJ and there is more time to summarize motor unit recruitment.

But power still increases because F goes up. The kid can hit you harder with a 500 than a 275, since he's not just exploding -- he's applying force after his acceleration. The tragedy here is that F is trainable and t is really not. You can radically increase the 18" kid's power even if you can't make him more explosive. Modern S&C has wasted lots of everybody's time, money, and potential with RFD "training" when College Algebra could have saved them some time.

Note: No posts from morons on the internet who say they can double your "vertical jump" or turn lead into gold will be approved.

[Ray Gillenwater]

I really enjoyed this. Thanks for posting, Adam and thanks for the detailed reply, Rip!

[adamanderson]

The equation for Power is P = (F x d)/t, where F is force applied to the system, d is the distance over which the force is applied, and t is the time over which the force is applied. So in this case, F is strength, d is determined by the test, and t is your explosive ability -- the ability to display strength quickly.

Yeah, my bad. I know that P = (F x d)/t. By N/s i.e. F/t, I meant the Force produced in the time that it takes to perform the jump before becoming airborne. But of course another variable is required to measure it, in this case the distance of the concentric portion of the movement, d.

The SVJ is a measure of your ability to generate enough force within the time it takes to perform the concentric phase of a jump, to accelerate your body's mass upward to impart sufficient velocity and therefore sufficient momentum to it, that it continues upward after the force production between your feet and the ground has stopped. The distance upward is a direct measurement of the force produced in the .25 seconds the contraction takes place

I completely understand.

When we take the kid from 275 to 500, the algebra shows us that his P goes up, even though this does not affect his SVJ proportionally -- doubling his squat does not double his SVJ, no way, not even close. This is due to the fact that the SVJ does not depend on max force production, because you're only jumping against your bodyweight. A true 1RM force production event only occurs under a 1RM load, which is not an instantaneous power display but rather a summation event. And this time constraint is why the clean is much more influenced by an increase in strength, because it takes maybe 5-6 times as long as the SVJ and there is more time to summarize motor unit recruitment.

I think my question about diminishing returns can flow from this. You said that Power goes up when F increases, and looking at the equation and P being directly proportional to F, this must inevitably be true. Since the jump takes such a short time to perform before gaining air, the F in that instance doesn't have sufficient time to increase, meaning that the Power IN THE PARTICULAR INSTANCE OF A SVJ of someone doesn't increase with an improved squat, so the SVJ remains the same no matter how strong one gets. As compared to a C&J or snatch, which takes a lot longer, so one has more time to approach ones max Force production ability, it takes longer because the weight is heavier and the distance of the movement is greater. Totally understood. With that said, wouldn't there be an optimal point for a person's SVJ (not by much, but every mm counts)? Say it takes .25s to push off the ground, if one is strong enough to maximize the F in the P in that .25s time, if one were to keep gaining strength and gains e.g. 30lbs of weight, but the F in the P remains the same due to the t, wouldn't it clearly follow that the SVJ is compromised? Same power, only more weight. It seems that this would also apply to things like high-jump, long-jump, sprint (more like .1s), pitching, etc.

But power still increases because F goes up. The kid can hit you harder with a 500 than a 275, since he's not just exploding -- he's applying force after his acceleration.

This is an insightful angle; anytime a movement takes sufficient time to approach max Force, high max Force is good to have ... which means most cases. Arm throws in wrestling are "explosive", but they take a lot longer than .25s.

Apologies for the aside, but this is somewhat related: is there a weight at which a person has optimal strength/weight ratio? I mean, if there is, wouldn't that always be ones best bet when competing in strength-based weight class sports? Or does strength increase proportionally to weight, making ones genetic strength maximum = ones p4p strength weight? I mean stuff like powerlifting. Boxing and the like get more complex, since there are countless variables like height, reach, strength vs speed, cardio, etc.

[Mark Rippetoe]

With that said, wouldn't there be an optimal point for a person's SVJ (not by much, but every mm counts)? Say it takes .25s to push off the ground, if one is strong enough to maximize the F in the P in that .25s time, if one were to keep gaining strength and gains e.g. 30lbs of weight, but the F in the P remains the same due to the t, wouldn't it clearly follow that the SVJ is compromised? Same power, only more weight. It seems that this would also apply to things like high-jump, long-jump, sprint (more like .1s), pitching, etc.

You're trying to maximize your SVJ performance? Why? It's a test, the results of which indicate genetics and potential. Maximizing the test is not the point of this particular test. It's like a blood test, not the SAT.

is there a weight at which a person has optimal strength/weight ratio? I mean, if there is, wouldn't that always be ones best bet when competing in strength-based weight class sports? Or does strength increase proportionally to weight, making ones genetic strength maximum = ones p4p strength weight? I mean stuff like powerlifting. Boxing and the like get more complex, since there are countless variables like height, reach, strength vs speed, cardio, etc.

At the IPF Worlds, how tall are the 105 kg guys?

[adamanderson]

You're trying to maximize your SVJ performance? Why? It's a test, the results of which indicate genetics and potential. Maximizing the test is not the point of this particular test. It's like a blood test, not the SAT.

I understand, I'm just trying to get a grip on the theory of the situation. Concretely, if the Force applied during those .25s = X, and can never be anything above X because of the individual's genetic limit for how much Force he can produce in .25s, wouldn't ones theoretical SVJ max be at the point where he's strong enough to produce X Newtons, while weighing as little as possible? Simply, the height of the jump depends on the total Force produced, and on his mass. F remains the same, m is manipulable. So, at Force X, it would seem to be optimal to weigh as little as possible. Again, this is out of pure interest. I'm not questioning the importance of strength for someone who tackles people and is required to drive through them for longer than .25s, and whose tackles also benefit from weighing a lot.

At the IPF Worlds, how tall are the 105 kg guys?

Frankly, I don't know s*** about PL. I'm just thinking that IF there is a p4p strength point for an individual, then that would be where he should compete, and I suppose that if he's at 30% BF, he should lose some of it in order to get to a lower weight class. I've searched the forums frenetically but I'm still not clear on whether that p4p place exists even.

[Mark Rippetoe]

If all you want to do is see how high you can jump, it would be good to not weigh very much. True thing.

[adamanderson]

If all you want to do is see how high you can jump, it would be good to not weigh very much. True thing.

Lol, yes it's pretty obvious, I trust myself ... but verify.

Maybe the p4p strength question is off-topic; should I post another thread with the question? I've searched for the answer but haven't figured it out yet. All I'm asking with regards to that is whether people have p4p strength sweetspots (given a specific BF%, obviously!!!).

[adamanderson]

Coach,

I've been binging all of your stuff and tried to infer a conclusion about this, but I'm still not absolutely sure; is there an optimal strength/weight ratio for a person, a point in weight where they're at their strongest? I mean, first of all, of course there is -- a person can double their squat without doubling their bodyweight, so there is better and worse, hence there is one that is best. My question is about where that point might be.

My understanding thus far, from listening to Ask Rip, reading on here, and thinking about it, is that:

The more muscle mass one gains, the higher ones muscle mass percentage, i.e. muscle mass per bodyweight, is. Muscles are what generate Force, i.e. what determine ones strength. Therefore, the more muscle that one has, the stronger one is (more or less, yes yes bodybuilders are bigger but not stronger than ... I know), not only totally, but also pound 4 pound.

... Simply put, the higher the percentage of your bodyweight that is capable of producing force (muscles), the stronger you are p4p, and that max muscle mass/total mass ratio, would obviously be attained by having as much muscle as possible. This is of course assuming a low BF%, since that would also contribute to the muscle mass/total mass ratio. I get that X lbs of muscle mass can produce different amounts of force, so this is of course also assuming that one has "maxed out" on the force production ability that is possible for the X lbs of muscle mass.

My guess is that this is what you meant by "How tall are the 105kg guys at the IPF?". Meaning that two guys at a given weight, one is short, the other is tall, they weigh the same (and have roughly the same BF%). The short guy has more muscle mass/bodyweight. The shorter guy always wins (assuming that he's considerably shorter, I don't mean that he's 6'1 and the "tall" guy is 6'2).

... he has more total muscle, hence he has a higher muscle mass/bodyweight ratio, hence more of his bodyweight is capable of producing force, hence he is stronger than the tall guy, hence he is p4p stronger -- meaning that the bodyweight at which an individual's max strength/weight ratio (max p4p strength) is, is equal to the heaviest bodyweight that he can get to with his genetics (and assuming a low BF%).

The reason why I'm not sure whether the logic holds, is that I've only recently started to think about this and may therefore be ignorant to a plethora of info that'd collapse the argument. I've also seen you say that one ought to have a "damn good reason" to cut weight for a PL competition, like competing for the glory of a world title. So I'm wondering if what goes into that damn good reason, could be that max p4p strength is NOT= max total strength (at low BF%). Of course, if e.g. the guys at a lower weight class all suck, a weight cut might be wise. But that's extra stuff.

... so yeah, my only question is: at what bodyweight is the p4p strength max found, is it = the bodyweight at which max total force production ability (i.e. strength) for that person is found (+ low BF%), and if not, what is it?

[Mark Rippetoe]

You keep asking the same question.