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cadence

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Tom A.

Oct 12, 09 10:59

Post #126 of 523 (852 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

In Reply To:

Hi Frank. Thats what i said. what I don't understand is why a rider would have both a short crank and a low cadence. Isn't that counter intuitive ? Wouldn't the high torque required be a problem if they weren't compensating by upping their cadence ? Any thoughts ?

Here is my take on crank length. I don't think crank length matters much except for triathlon or tt-ing. The difference between 170 and 175 is about 3%. Such a change is easily within the normal range of motion limits of the joints so should not account for much of a mechanical leverage difference in the legs or joints. Only when the cranks get way too long or way to short should this be much of a problem for most people.

What seems to matter most from an overall efficiency point of view is pedal speed. To keep pedal speed the same if we change crank length 3% would simply require changing the cadence 3% or changing a 75 cadence to 77.25 or 72.75 (depending upon whether you went shorter or longer respectively). This is hardly a problem to deal with in racing as the difference between a 14 and 15 tooth cog is over 6%.

So, we see shorter cranks provide almost zero "leverage" difficulties and even if we went very short this could be easily be made up for by different gearing to keep pedal speed the same for the same power. So, there is nothing lost in climbing by going to shorter cranks if we gear the bike appropriately. But, shorter cranks offer other advantages.

1. It will take less energy to make them go around one revolution as the up and down excursion of the thigh is less by twice the crank length difference. This means one can achieve higher rpm for the same energy expenditure so one is less likely to "spin out" on the down hills. So, higher top end speed on the downhills.

2. The lesser thigh excursion means that we will be less cramped when we are in the aero position. This should allow the rider to either generate more power in their aero position or get lower without losing any or much power. So, higher speed on the flats.

Any or all of these differences should allow the cyclist to race better.

The only question for me is how short is too short? It is why I have recently extended the adjustability range of our basic PowerCranks to go as short as 155 to allow the user of any size to experiement with this some.

Not to mention better cornering clearances for those of us who do crits ;-)

Actually...although Frank might think that all I ever do is disagree with him...I have to say, on this point I think he's basically got it right :-)

Please tell me that you simply overlooked his claim #1! ;-)

Doh...yeah (sheepish), I kind of skimmed over that part...

Well, in my defense, I did say "basically" ;-) Sorry Frank, I do have to take exception with that first claim though...but otherwise, the general gist of your comment (i.e. there's no harm, and there could be some advantages with shorter than "normal" cranks) I agree with.

Slowman

Oct 12, 09 11:03

Post #127 of 523 (850 views)

Re: cadence [Frank Day] [In reply to]	Can't Post

"Johnnyo had indicated that Brett was interested in lowest HR. That certainly suggests at least a minimum of testing to me looking for efficiency."

then i think you're back to having to explain to the rest of the cycling world why their cadences are all wrong.

this has been discussed on forum boards and around the gookinaid cooler for at least the 30 years i've been bike and then triathlon racing. nevertheless, as effort and intensity increases in cycling races, cadence increases. you can say it shouldn't. nevertheless, it does. maybe andy can find me the study showing that, for a 1hr test, 95rpm is best. but i haven't seen it. yet, what is the typical cadence in timed racing by the world's best? were they all to ride with cadences of 75 or 80, their HRs would be lower, based on the plethora of literature. but they don't typically ride that way.

my thesis always has been, and remains, vary from the consensus formed by the best exemplars in a sport at your own peril. slow turners are in the big minority once you get to the world class level. but, if you want to turn your cranks slow, you be my guest.

Dan Empfield
aka Slowman

Andrew Coggan

Oct 12, 09 11:09

Post #128 of 523 (841 views)

Re: cadence [Slowman] [In reply to]	Can't Post

In Reply To:

maybe andy can find me the study showing that, for a 1hr test, 95rpm is best. but i haven't seen it.

You must not have looked very hard. ;-)

http://www.ncbi.nlm.nih.gov/pubmed/15503124

(Okay, it was a 30 min test, not a 1 h test, and their finding was that 80 rpm was best...but still...)

bjorn

Oct 12, 09 11:10

Post #129 of 523 (841 views)

Re: cadence [Slowman] [In reply to]	Can't Post

The difference is that while I think we are largely the same you seem to think we're exactly the same in all instances and in every way. The examples I have provided have may have no value in themself, like you pointed out with your goat milk joke or whatever, but no matter what you say it does show there can be small individual differences. That's all I'm saying and I have never said everyone are completely different. In medicine, diet, sport and so on there is of course a standard or general norm to start with that works for most but I really don't think it's very controversial that some deviate a little from that.

(This post was edited by bjorn on Oct 12, 09 11:28)

Slowman

Oct 12, 09 11:17

Post #130 of 523 (832 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

"Okay, it was a 30 min test, not a 1 h test, and their finding was that 80 rpm was best...but still"

if they tested cadences of 80 and 100 and, even at this relatively short test 80 was better, how does that prove that 95 is best in a 1hr test? don't you think in a 1hr test the evidence would have been skewed even more toward the lower cadence?

Dan Empfield
aka Slowman

Andrew Coggan

Oct 12, 09 11:23

Post #131 of 523 (822 views)

Re: cadence [Slowman] [In reply to]	Can't Post

In Reply To:

It doesn't - I was merely pointing out that several studies have directly examined the effects of cadence on performance, with that being just an example. You, OTOH, made it sounds as if no such studies had ever been performed.

Slowman

Oct 12, 09 11:27

Post #132 of 523 (816 views)

Re: cadence [bjorn] [In reply to]	Can't Post

"The difference is that while I think we are largely the same you seem to think we're exactly the same in all instances and in every way."

no, i don't, and i never said that. but i'm struck by the frequency with which those who focus on the outlier accuse me of this. what i have said, and often, is that our sameness trumps our differences when it comes to medicine, science, ergonomics, sport, and the like. that it is a safer bet to err on the side of conformity than on the side of novelty. i think it's safer, as a coach, to teach conformity, and have the variances from conformity be minor rather than major.

so, i think you teach your IM athletes to pedal at something like 84, and maybe that's 82, and maybe that's 86, but you're somewhere in that range. why? because that's what most of the best male power files show.

if you want to pedal at 70 or 75, fine. if you want to teach your athletes that, fine. but i think the onus is on you to demonstrate why you're correct, since you're teaching an outlier's technique.

now, if you're saying, no, you're not teaching that, you're saying that people should just pedal however they want, fine, but then you're of no use as a coach. why should i pay you to tell me i should just do what i feel like? i'll just make up my own workouts, my own bike position, my own technique, because, as you say, everybody is different.

Dan Empfield
aka Slowman

Devlin

Oct 12, 09 11:31

Post #133 of 523 (804 views)

Re: cadence [Frank Day] [In reply to]	Can't Post

In Reply To:

1. It will take less energy to make them go around one revolution as the up and down excursion of the thigh is less by twice the crank length difference. This means one can achieve higher rpm for the same energy expenditure so one is less likely to "spin out" on the down hills. So, higher top end speed on the downhills.

If you can spin faster for the same energy, wouldn't that make you MORE likely to spin out on the downhills?

John

Sponsors: Rudy Project

That is 11 dimensions of awesome. Yes, string theory is necessary to fully appreciate the meta-nature of your post.-DaveRoche

Andrew Coggan

Oct 12, 09 11:33

Post #134 of 523 (803 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

In Reply To:

I was merely pointing out that several studies have directly examined the effects of cadence on performance, with that being just an example.

BTW, here is another one in favor of "slugging it out" (at 83 +/- 6 rpm) on an ergometer, this time during a ~12 min effort:

http://www.ncbi.nlm.nih.gov/pubmed/16572372

(This post was edited by Andrew Coggan on Oct 12, 09 11:34)

bjorn

Oct 12, 09 11:49

Post #135 of 523 (789 views)

Re: cadence [Slowman] [In reply to]	Can't Post

In Reply To:

"The difference is that while I think we are largely the same you seem to think we're exactly the same in all instances and in every way."

no, i don't, and i never said that. but i'm struck by the frequency with which those who focus on the outlier accuse me of this. Maybe it's because you're making a big deal out of relatively small details that are not really that much of a deviation outside the norm if you look at the big picture. that it is a safer bet to err on the side of conformity than on the side of novelty. i think it's safer, as a coach, to teach conformity, and have the variances from conformity be minor rather than major.

Certainly, but you should also maybe be aware that some might not respond to training stress etc in exactly the same way and be prepared to be flexible and perhaps make small corrections to accomodate.

so, i think you teach your IM athletes to pedal at something like 84, and maybe that's 82, and maybe that's 86, but you're somewhere in that range. why? because that's what most of the best male power files show.

if you want to pedal at 70 or 75, fine. if you want to teach your athletes that, fine. but i think the onus is on you to demonstrate why you're correct, since you're teaching an outlier's technique.

now, if you're saying, no, you're not teaching that, you're saying that people should just pedal however they want, fine, but then you're of no use as a coach. why should i pay you to tell me i should just do what i feel like? i'll just make up my own workouts, my own bike position, my own technique, because, as you say, everybody is different. I don't know what self selecting ones cadence has to do with bike positions, scheduling workouts etc. I think a good training schedule has a much bigger impact in the grand scheme of things than a few rpm here and there and I don't think it has to be one or the other. Iow just because you feel best pedalling at 82rpm instead of 84 doesen't mean you think you can't benefit a lot from working with someone on the more important stuff.

tilburs

Oct 12, 09 12:02

Post #136 of 523 (768 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

As Andy says there's a bunch of papers out there and if one reads the conclusion of the paper shown in the link carefully, particularly the reference to "optimal", I think it says it all really. I would only perhaps add that muscle fibre type balance might skew an individual either way a handful of rpm.

http://www.fims.org/...asp?pageID=213202031

Reading several papers on this and from coaching experience IMO "preferred" cadence is HIGHLY related to the power output.

Regards

David
David T-D
www.physfarm.com

Slowman

Oct 12, 09 12:03

Post #137 of 523 (767 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

"I was merely pointing out that several studies have directly examined the effects of cadence on performance, with that being just an example. You, OTOH, made it sounds as if no such studies had ever been performed."

you didn't read the entire thread (and who could blame you? it's pretty long). higher up in the thread you'd note that i acknowledge (and own a copy of) dozens of such studies. my comment was simply to point out that cadence is the "french paradox" of cycling literature: what academia "proves" is at a wide variance from that cyclists actually do. i've seen energetic optimals at 50rpm, 60, 70, and i'm guessing this is just a matter of the intensity of the test. but i've never seen anything higher than somewhere in the 70s for a test of any decent duration (hence my asking you whether there's a study i missed, i figured you would know).

you and i come from an era of big cranks and cadences in the low 80s, but modern riders don't seem to ride that way, other than the occasional grabsch and gonchar. i'm looking for the study that shows that the cadences elite riders typically use are in fact what's best in the lab as well. haven't found that yet.

not to belabor, but if a study shows that cyclists in a 12min performance do best at 83rpm, they're about at the cadence used by the best male triathletes on an 8hr event. there just seems to be this 20 beat variance between what academia suggests is best for a performance versus what is actually used by the sport's elite.

Dan Empfield
aka Slowman

Andrew Coggan

Oct 12, 09 12:15

Post #138 of 523 (751 views)

Re: cadence [Slowman] [In reply to]	Can't Post

In Reply To:

Actually, I did.

In Reply To:

higher up in the thread you'd note that i acknowledge (and own a copy of) dozens of such studies.

Actually, your 1st reference to science in this thread was where you strongly (and wrongly) implied that Alquist et al.'s results made it "case closed". Your 2nd reference was a few posts later, when you alluded to studies of efficiency. You didn't, though, talk about studies of actual performance until that post to which I responded (and I'm still not convinced that you have actually read the studies in question).

In Reply To:

if a study shows that cyclists in a 12min performance do best at 83rpm, they're about at the cadence used by the best male triathletes on an 8hr event. there just seems to be this 20 beat variance between what academia suggests is best for a performance versus what is actually used by the sport's elite.

Two differences:

1. Ergometer vs. outdoor cycling.

2. Non-elite vs. elite.

Slowman

Oct 12, 09 12:17

Post #139 of 523 (746 views)

Re: cadence [bjorn] [In reply to]	Can't Post

"you should also maybe be aware that some might not respond to training stress etc in exactly the same way and be prepared to be flexible and perhaps make small corrections to accomodate."

i've got no problem with that. i think a range is a lot more prudent than a fixed number. just, when the range is so big that it loses its meaning, then, you're back to, "do whatever you want."

"just because you feel best pedalling at 82rpm instead of 84 doesen't mean you think you can't benefit a lot from working with someone on the more important stuff."

there, i think we came together, you and i. if you think 82 just is a better cadence for you than 84, i've got no quarrel (obviously, since some posts up i believe i said that anything within 2 beats either way of 84 seems to be where the best IM pros tend to be).

what you seem to say is that bike technique, maybe position, these are the "minor things," but workouts, like chemotherapy, that's major, and that's where "sameness" starts to become more important to you. but some other coach might disagree with your workouts, arguing that "everybody's different" and what you think is important might be wholly inappropriate for someone else.

and this is where it gets so tricky. when everybody picks apart the consensus way a sport ought to be done because they don't think one part or another is important, you end up with no consensus. which is fine, except, if i'm a coach, or an academic, or a medical doctor, or a jurist, or a businessman, i think i'll go further standing on the shoulders of those who've come before me and who've found success. i think it's okay to deviate, i think you just ought to be wary of deviation, and you should do so only if you think you have a very good reason. otherwise, the wager is against you. you apparently disagree with this, and that's fine.

i'll be offline for awhile, i'm off to swim, where i'm going to exercise the theme of "sameness" and attempt to emulate your very good swim technique.

Dan Empfield
aka Slowman

Frank Day

Oct 12, 09 12:19

Post #140 of 523 (742 views)

Re: cadence [Slowman] [In reply to]	Can't Post

In Reply To:

Actually, as I have thought about this (and I think about this stuff a lot) I think explaining it is pretty easy.

Cycling and cycling racing, has been around for a very long time. If you look at the average commuter in China or europe I think you will find them riding at a cadence of 40-50 or so. Very low cadences. But, these folks are not interested in racing, they are interested in getting to their destination and not being all sweaty. Racers, on the other hand are interested in racing. Cycling racing involves very little time-trialing so most cyclists do not focus on maximizing this effort but rather maximizing the group racing dynamic. This means always being ready to respond to different efforts. High power efforts require higher cadences so these riders have learned that it is better to give up a bit of efficiency when riding at low power in order to be able to rapidly increase their power to jump ahead of (or keep up with) opponents. It is a tactical decision that goes to the race dynamic. Because that is what it takes to win in those kinds of races these riders have somehow, mistakenly, determined that higher cadences are better for all efforts.

Triathletes, knowing they are not as good at cycling, tend to look at good cyclists and follow their lead. It is a mistake to do so as triathletes do not do the same kind of racing. But, they do.

In Reply To:

my thesis always has been, and remains, vary from the consensus formed by the best exemplars in a sport at your own peril. slow turners are in the big minority once you get to the world class level. but, if you want to turn your cranks slow, you be my guest.

See above. It is sort of funny to me that there are threads here arguing over whether Chrissy could have saved another 5 minutes or so on her bike split if she had chosen a better aerodynamic bike (unlikely in my opinion) but ignoring the fact that her different pedaling style seems to have cut about 20 minutes or so off her bike split from everyone else. Chrissie's dominance is coming from a better engine and from an even better optimization of the superior engine she has, IMHO.

I would suggest that you understand what the science says about pedaling, try to understand why cyclists might deviate from what the science says is best (see above), and then understand why it might be better to try to explain why the most dominant triathlete of recent times is so dominant rather than trying to explain why she is an outlier and shouldn't be emulated. What Chrissie is doing is in keeping with what the science says should happen. Whether this was a deliberate decision from testing or whatever by her and Brett is not important. She is an outlier on cadence and she is dominating the bike. Unless you think she is doping, what else could it be? Her parents were not born on Krypton and she arrived in a rocket ship, AFAIK. The world better pay attention or she is going to win an awful lot of these things.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Frank Day

Oct 12, 09 12:28

Post #141 of 523 (730 views)

Re: cadence [Tom A.] [In reply to]	Can't Post

In Reply To:

Please tell me that you simply overlooked his claim #1! ;-)

Well, I am waiting for you guys to show me where that statement is wrong. You can show me the math or you can show me a study. But, last I looked F=ma. If at BDC or TDC each thigh is stopped and at 90� later it is moving up or down at maximum velocity the "force" to cause that "acceleration" had to come from somewhere. Show me how it wasn't the muscles and I will concede defeat on this point.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Slowman

Oct 12, 09 12:29

Post #142 of 523 (728 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

"You didn't, though, talk about studies of actual performance until that post to which I responded (and I'm still not convinced that you have actually read the studies in question)."

have it your way.

Dan Empfield
aka Slowman

Andrew Coggan

Oct 12, 09 12:32

Post #143 of 523 (725 views)

Re: cadence [Frank Day] [In reply to]	Can't Post

In Reply To:

I am waiting for you guys to show me where that statement is wrong.

http://en.wikipedia.org/...aw_of_thermodynamics

Frank Day

Oct 12, 09 12:34

Post #144 of 523 (719 views)

Re: cadence [Devlin] [In reply to]	Can't Post

In Reply To:

If you can spin faster for the same energy, wouldn't that make you MORE likely to spin out on the downhills?

John

In cycling if you are in your biggest gear (54/11 for example) and going down hill the top speed you can power is determined by the maximum cadence you can make your legs go around. The higher that is (shorter cranks) the faster you can go before you are forced to coast. So, you would be less likely to spin out. That is what I meant.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Frank Day

Oct 12, 09 12:37

Post #145 of 523 (712 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

In Reply To:

I am waiting for you guys to show me where that statement is wrong.

http://en.wikipedia.org/...aw_of_thermodynamics

LOL. Show that this applies to this specific instance. The contractile efficiency of the muscle is around 40%. The overall pedaling efficiency of the cyclist is about 20%. Account for all the losses without invoking losses from the pedaling motion itself.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Frank Day

Oct 12, 09 12:41

Post #146 of 523 (703 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

In Reply To:

Two differences:

1. Ergometer vs. outdoor cycling.

2. Non-elite vs. elite.

Could you explain why you feel these would make a substantial difference?

All you are saying here, it seems to me, is that "because most studies are done on ergometers using non-elite cyclists they do nothing to counter my bias."
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Frank Day

Oct 12, 09 12:50

Post #147 of 523 (1339 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

In Reply To:

maybe andy can find me the study showing that, for a 1hr test, 95rpm is best. but i haven't seen it.

You must not have looked very hard. ;-)

http://www.ncbi.nlm.nih.gov/pubmed/15503124

(Okay, it was a 30 min test, not a 1 h test, and their finding was that 80 rpm was best...but still...)

"This study demonstrated that elite cyclists perform best at their most efficient cadence despite the maximal energy turnover rate being larger at a higher cadence."

What wasn't in the abstract but might be in the body is what power these folks were at. Can you help us out with that answer?

If they were at 400 watts it would suggest to me that even if 80 rpm was optimum for these folks that those who ride at substantially lower power (and for substantially longer times) would be much better off at substantially lower cadences.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

gciriani

Oct 12, 09 17:27

Post #148 of 523 (1270 views)

Re: cadence [Andrew Coggan] [In reply to]	Can't Post

Doesn't optimal cadence depend on the Force-Velocity curve for the particular muscle being considered? And isn't the Force-Velocity curve different for each individual? If this is true, wouldn't then optimal cadence be different for each individual?
Giovanni Ciriani
www.GlobusSHT.com

Frank Day

Oct 12, 09 17:35

Post #149 of 523 (1263 views)

Re: cadence [gciriani] [In reply to]	Can't Post

In Reply To:

We will see what Dr. Coggan says but I would say that is just one of the factors involved in determining optimum cadence. I would suggest that no one can know their optimum cadence without testing and that their optimum cadence will probably change as they train more/improve.
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

Frank Day

Oct 12, 09 17:54

Post #150 of 523 (1246 views)

Re: cadence [Frank Day] [In reply to]	Can't Post

In Reply To:

maybe andy can find me the study showing that, for a 1hr test, 95rpm is best. but i haven't seen it.

You must not have looked very hard. ;-)

http://www.ncbi.nlm.nih.gov/pubmed/15503124

(Okay, it was a 30 min test, not a 1 h test, and their finding was that 80 rpm was best...but still...)

While this is not the entire study it does give an insight we didn't have before that seemingly supports what I have been saying all along.

http://www.nih.no/...tes/page____916.aspx

"It was found that the most economical cadence increased with increasing workload."
Frank, Inventor of PowerCranks
- - - - - - - - - - - - -
To be a top ten finisher in the Ironman World Championships with a time of 16:30 or so is easy. . . as long as do the first one.

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