Strength and cycling controversy



acoggan said:
Once again you're (deliberately??) missing the point: there will be no significant difference in cadence after just ~3 pedal revolutions

The slight difference in that cadence is relevant. Talk to many people doing the event about their different gear choices and how it affects them, even in the first 25 meters. This is easy to see if you just sit and watch a bunch of riders at an event like districts or masters nat's. Watch the 500's, the kilos, and especially the team sprint starts, and not just the first rider, but all three riders to observe the relative differences in strength off the line vs. their first lap times and finish times.

Like I said, I do standing starts every week in training and a start with a 53x17 is quite different from one done with 53x16. It is the very first 3-4 pedal strokes that I notice it the most, and then again later in the acceleration phase, and again towards the finish.

I've done team sprints using different gearing but the same riders with me and a difference in gearing like you mention matters by up to 10-15 feet over the first 25-50m. When I do a team sprint first lap a gear difference of just 2-3" is very important for the start, the later phase of acceleration, and the finish phase. Go to Masters Nat's and talk to 10 of the fastest first lap guys.

acoggan said:
Indeed, in studying national team athletes Stone et al. found that there no difference in the time required to cover the first 25 m when the riders used such "markedly" different gears.

Didn't you say it was up to half a second difference? If so, that is huge. Let's see ALL of that data.

The race is far longer than 25m and individuals who don't race for the national team have come up with variations of gearing and cadence to match their strength off the line, and their abilities later in the event to produce their lowest overall time in the event.
 
WarrenG said:
The slight difference in that cadence is relevant.

Again, no. See if you can keep up this time...

Strength, by definition, is the maximal force generating capacity of muscle, which happens to occur at zero velocity (ignoring velocities less than zero, i.e., eccentric contractions, that is). With any increase in velocity above zero, force falls off progressively, with this decline in force being essentially linear when cycling. Thus, short of performing an isometric contraction against the pedal, the best approach for quantifying one's pedaling strength is to measure force during the initial portion of this decline, and back-extrapolate to zero velocity (as I have illustrated here: http://home.earthlink.net/~acoggan/misc/id6.html and here: http://home.earthlink.net/~acoggan/setraining/id3.html). Even if you don't actually perform the back extrapolation, however, whether you perform such efforts in an 84" or 90" (or bigger) gear makes no difference, because for the first 25 m (~3 pedal revolutions) you're still operating very close to the Y-axis, i.e., at close to your maximal force. Indeed, to argue you otherwise, as you have repeatedly done, is equivalent to saying that your mass is greater when you stand on the end of a long vs. a short diving board.

WarrenG said:
Didn't you say it was up to half a second difference?

That was at the one lap mark, not the 25 m mark.

WarrenG said:
Let's see ALL of that data.

See Stone's paper.

WarrenG said:
The race is far longer than 25m and individuals who don't race for the national team have come up with variations of gearing and cadence to match their strength off the line, and their abilities later in the event to produce their lowest overall time in the event.

I never said that gearing didn't matter to performance (i.e., time required to cover a set distance) in competition - only that it makes no difference when quantifying your maximal force generating capacity when pedaling. Indeed, Jim Martin's inertial load ergometer could be considered the "gold standard" by which such measurements are made, and it is equivalent to doing a standing start in only a 39x17 or thereabouts (maybe 39x19 for a big dude like you).

Back to the original question: to appreciate that power/mass is a better indicator of performance ability than absolute power even in flat events such as the kilometer, you only have to look at the data for the three World Champions (i.e., Sean Eadie, Shane Kelly, Anna Meares) in Jim's study. Their absolute peak powers when performing a maximal standing start effort were ~2500, ~2000, and ~1400 W, respectively. Based on your position that absolute power is what matters the most, you'd expect from these data that Eadie would be much faster than Kelly who would be much faster than Meares. Yet, after 15 s Eadie and Kelly are both going ~18 m/s, and Meares is hanging tough at ~17 m/s. This is explained, of course, by the fact that Eadie weighs 96 kg, Kelly weighs 87 kg, and Meares only 68 kg - this makes their peak powers in W/kg much more comparable at ~26, ~23, and ~21 W/kg, respectively. Clearly, then, the initial rate of acceleration is more closely related to power in W/kg than in W alone, as you'd expect - in fact, as required - by the physics involved.

The fact that Kelly can compete with Eadie, and even more dramatically, that Meares can come close to Kelly (through 500 m), is further explained by their differences in CdA: 0.332 m^2 for Eadie, 0.215 m^2 for Kelly, and 0.186 m^2 for Meares. While mass is a relatively poor predictor of aerodynamic drag, it is a predictor nonetheless - thus, expressing the data in W/kg is also better than W even after the acceleration phase is past and overcoming aerodynamic drag is the major consideration. (Of course, W/CdA would be better still, but that isn't the issue at hand.)
 
acoggan said:
Again, no. See if you can keep up this time...

Yes, the guy who has NEVER done the event has trouble explaining his opinions about the event to a reigning national champion in the event... Not sure which is more in evidence here, your ignorance or your arrogance.

Your point of view would be more useful if your limited, second-hand observations about a few world-class elite riders were at least combined with a reasonable amount of real world experience and observations that extended well beyond a few world-class elite riders.

And BTW, half a second is HUGE in the first lap of these events.
 
After your up to a pre jump speed,....say 26 mph, and then to max speed, wouldnt absolute power be of more importance as the main form of resistace becomes wind/frontal area.
 
WarrenG said:
Yes, the guy who has NEVER done the event has trouble explaining his opinions about the event to a reigning national champion in the event... Not sure which is more in evidence here, your ignorance or your arrogance.

I think it is your lack of understanding of simple physics...

WarrenG said:
Your point of view would be more useful if your limited, second-hand observations about a few world-class elite riders were at least combined with a reasonable amount of real world experience and observations that extended well beyond a few world-class elite riders.

Actually, the broader the range of abilities over which one examined the data, the easier it would be to find a correlation between W/kg and performance. Of course, you'd realize that if you knew anything at all about statistics.

WarrenG said:
And BTW, half a second is HUGE in the first lap of these events.

I never said it wasn't. What I said was that, in Stone's study, using an 84" vs. a 90" gear had no significant impact on the time required to cover 25 m. This is as expected, given that even at that point cadence would have been only about half of that resulting in maximal power output. IOW, the rider's were limited by the maximal force that they could generate relative to their mass: http://www.glenbrook.k12.il.us/GBSSCI/PHYS/CLASS/newtlaws/u2l3a.html
 
Billsworld said:
After your up to a pre jump speed,....say 26 mph, and then to max speed, wouldnt absolute power be of more importance as the main form of resistace becomes wind/frontal area.

The primary resisting force changes from inertial to aerodynamic in nature as you accelerate. Even at higher speeds, however, power relative to mass is a better predictor of performance ability than power alone, because aerodynamic drag is correlated with body size, of which mass is one measure (height or body surface area would be even better in this context, but the issue is W vs. W/kg).
 
acoggan said:
Actually, the broader the range of abilities over which one examined the data, the easier it would be to find a correlation between W/kg and performance. Of course, you'd realize that if you knew anything at all about statistics.]

Andy, those of us who actually do the events care very little about averages and correlations for an entire population. In bike racing and preparing ourselves to do an event each individual approaches the event in a manner (preferably) best-suited to their abilities and potential. Your conclusions drawn from a very, very small sample of the entire population of bike racers may offer some help, but in some cases your conclusions are contrary to what is actually happening for many bike racers in the real world.

Here is some data from the real-world. I have higher w/kg than Larry Nolan and Jeff Fillerup and I know this because I can accelerate faster than them from rest at most cadence ranges. We are all about the same age, weight, and height. They can both beat me in a kilo race by about 3 seconds. Last year in the 45-49 nat's kilo Gil Hatton beat the next three top riders by not a lot, but the difference in w/kg heavily favors Gil-it's not even close. (I raced against 3 of those top 4 last year.) In 2004 the second place rider in the kilo had much better acceleration than the rider who won, and that win was a by a tenth of a second. I sprinted against each of them that week on the same day and the differences in watts/kg were quite clearly in favor of the second placed rider, and the kilo winner had higher absolute watts.

As some of us already know, w/kg tells only a small part of the total performance during kilos and team sprint events in the real world, and in many real-world cases, w/kg offers virtually no insight about the performances of an individual rider relative to their competition.
 
OK , Feeling humbled by the whole Mears comment:( .....Are these massive #s by the elites all mesured in the first 15 secs of a standing start? Do they make the same #s when they do a 200tt or similar events.? I heard a rumor that Eadie does. Then you look at Bos, and he leaves early and spins like a maniac. I heard Harnet was similar to that and his WR was in a 50x15 190rpm + -. (not completely sure of that) Is it possable that there is more than one way to look at performance in the sprints considering ones personal abilities?
 
Within my own experience, Bill's comment is more accurate than Andy's.

Aerodynamics are only part of the story. I can think of a half dozen riders I've sprinted against or done team sprint with at masters national and world championships who can outjump me at some speeds and cadence ranges but I can outjump them at other speeds and cadence ranges.

Also, some match sprinters, team sprint and kilo riders do their best with a position that is noticeably less aero than another rider's position. These are some of the reasons why we use a stopwatch and our eyes to evaluate our fellow competitors, not a scale and powermeter.
 
Billsworld said:
...Are these massive #s by the elites all mesured in the first 15 secs of a standing start? Do they make the same #s when they do a 200tt or similar events.? I heard a rumor that Eadie does. Then you look at Bos, and he leaves early and spins like a maniac. I heard Harnett was similar to that and his WR was in a 50x15 190rpm + -. (not completely sure of that) Is it possible that there is more than one way to look at performance in the sprints considering ones personal abilities?

Foul! Bill has resorted to calling upon the personal insight of a very famous pro track sprinter from the past! C'est bon!
 
Billsworld said:
OK , Feeling humbled by the whole Mears comment:( .....Are these massive #s by the elites all mesured in the first 15 secs of a standing start? Do they make the same #s when they do a 200tt or similar events.? I heard a rumor that Eadie does. Then you look at Bos, and he leaves early and spins like a maniac. I heard Harnet was similar to that and his WR was in a 50x15 190rpm + -. (not completely sure of that) Is it possable that there is more than one way to look at performance in the sprints considering ones personal abilities?


I would like to see how their numbers compare across different efforts, like standing starts vs 200m. I know there is a huge difference between my 5 second power in a 200m sprint compared to a short uphill sprint. I'm talking 400watts difference. Standing starts fall somewhere inbetween the two.

Soooooo, Andy, how should we be testing for 5 second power? It is very important to take data from simular situations for accurate comparison on your chart.
 
velomanct said:
I know there is a huge difference between my 5 second power in a 200m sprint compared to a short uphill sprint. I'm talking 400watts difference. Standing starts fall somewhere inbetween the two..

Uphill power can be influenced by the "dead spots" in your pedaling motion when momentum is not there to help you through them. Practice can help here too.

Different riders will find their maximum power for 5 seconds within different ranges of cadence. Some of this will be based on the riders' coordination and technique within those ranges. With practice you may be able to improve your power within certain ranges of cadence.
 
I am still unhappy about the Anna Mears thing. Thats no way to make friends! My sprints go from 350-400watts 25-28mph ...3 secs later 1500-1550+-. 10 secs later 975-1100+-. the speed will be 37-40mph @150-155 rpm in a 88"gear , and speed doesnt come till the watts are on thier way out. If I were a freak and could make 2000-2400 watts. I would jump in a huge gear . I dont know what the best can do in the top end, but I have to really focus to get any speed. For me peak speed comes in around 6-7 seconds past peak....I have to learn to hold it for another 5 sec. My question, or point was , are there different power profiles that will yeild a similar time. Bos with a 300+meter sprint or Baley with a 250 Both go 10.1 Honestly I have no clue VMan, I used to make more power on the uphill sprints. I make more from a jump on a flat or even a slight downhill now.
 
Bill,

If I can tell you any piece of advise that might help you here.

Take a look at 100m running sprinters, and how they relax when they hit top speed. Somewhere around the 40m mark. They then try and hang on to this stride as long as possible.

It's the same for bike riding. In a 200m TT, you try to wind it up to a point that will enable you to accelerate to top speed, yet at the same time conserve some energy. After you sit down you should soon be pedalling at your max. It is here where I try to relax and hold the speed. And then as I begin to enter turn 4 try and accelerate again. But if you are fighting it like a squat and your teeth are all clenched then you are losing speed and power.

Now, I don't no how all this correlates to this thread and power ratios vs cadense vs the square root of your ass. But thats how I do it!!
 
Bill,

If you really want to improve your 200m TT here is some advise.

Watch the 100m runners. They accelerate to 40m, then they relax and simply try and hold stride for the next 40m before gutting it out to the line.

It's the same for bike racing. You slowly acclerate to about 80%, then jump, and soon after you sit down you should be somewhere around your max cadense. Here you relax and try and hold it smoothly, don't fight the bike. And for me once I see turn 4 I try and accelerate again to the line.

Now, I don't know where all this fits in here. And I'am not sure where power vs cadense vs the square root of your ass makes any difference.

But thats how I do it!!
 
Billsworld said:
I am still unhappy about the Anna Mears thing. Thats no way to make friends! My sprints go from 350-400watts 25-28mph ...3 secs later 1500-1550+-. 10 secs later 975-1100+-. the speed will be 37-40mph @150-155 rpm in a 88"gear , and speed doesnt come till the watts are on thier way out.

After about 13 seconds of sprinting your power is still around 70% of peak. And you haven't yet done much training to extend your sprint. Interesting. :)

Consider the watts it takes to maintain 37 mph. It takes more watts to accelerate up to the 37mph. Now if you can be doing your acceleration within your opponent's draft or with some help from banking...

Billsworld said:
My question, or point was , are there different power profiles that will yield a similar time.

You will see this clearly when you watch a number of riders doing their 200mTT's. Some jump late and very hard, some just wind up gradually over a much longer distance. Some are slowing more than others as they approach the finish. You will have to experiment to see which approach or profile results in your lowest time. You will also have to use different profiles for different opponents.

Billsworld said:
...I used to make more power on the uphill sprints. I make more from a jump on a flat or even a slight downhill now.

I think it's because you're getting away from the raw strength you had from lots of lifting and now you are learning how to coordinate your muscles to perform well at fairly high rpm's.
 
If I were to take those sprints out another 5 secs or so, (as I would need to for the 200) I would most likely be in the 750-850 range...I hope. I will let you know when MR Lazyman fininshes his work. Just for a comparison. I do some high cadence sets after Starts. The cadence is usually in the 190 range. I try to hold it as long as possable 10-12 secs is all I am good for. Power at the very end is about 650. My guess is that a guy like Bos isnt using a 42x17 and is quite a bit higher than 650 at the end of his 200 tt:rolleyes: On the flip side to this debate...My guess is that "most" of those top elites have profiles that are similar, and @ nats. and states , you have a greater cross section of athletes and therefore more differeces in power profiles.If you look at elite track and field, the sprinters look like clones. They all explode and look even. Then you have a guy like Carl Lewis that wasnt the best starter, but looked like he had another gear in the 2nd half. Again in track n field, the 200 has been won by both 100/200 meter runners as well as 200/400 meter guys like Micheal Johnson...he was pretty good. If you could develop a power profile for a top 100 runner and a top 400 runner, the profiles would look different, yet they both might be awsome at the 200 as were Lewis(100/200) and Johnson 200/400. The question is : does the ability to choose a gear negate the differences in pesonal ability and make the power profile of a Bos look the same as an Eadie Ok now you can all set me on fire
 
WarrenG said:
Andy, those of us who actually do the events care very little about averages and correlations for an entire population.

But this entire discussion has been about the entire population.

WarrenG said:
Here is some data from the real-world. I have higher w/kg than Larry Nolan and Jeff Fillerup and I know this because I can accelerate faster than them from rest at most cadence ranges. We are all about the same age, weight, and height. They can both beat me in a kilo race by about 3 seconds. Last year in the 45-49 nat's kilo Gil Hatton beat the next three top riders by not a lot, but the difference in w/kg heavily favors Gil-it's not even close. (I raced against 3 of those top 4 last year.) In 2004 the second place rider in the kilo had much better acceleration than the rider who won, and that win was a by a tenth of a second. I sprinted against each of them that week on the same day and the differences in watts/kg were quite clearly in favor of the second placed rider, and the kilo winner had higher absolute watts.

Here's some more data from the real-world: my mom is still alive and kicking at more than 80 y of age, despite being a 2+ pack a day smoker her entire adult life. By your logic, this is evidence that smoking doesn't contribute to premature death, even though it is clear from epidemiological studies that it does.
 
velomanct said:
Soooooo, Andy, how should we be testing for 5 second power? It is very important to take data from simular situations for accurate comparison on your chart.

Basically in whatever manner consistently produces the highest value. That is, like VO2max maximal neuromuscular power is a physiological characteristic, and hence within certain limits is indepedent of the means by which it is determined.

To be more specific: to achieve maximal power requires reaching optimal cadence very quickly, before any significant muscle fatigue can develop - IOW, you need to "get on top of the gear" almost immediately. Provided you can do so (e.g., by performing a standing start in a very low gear, e.g., 39x17, or by coasting downhill to build up significant speed before initiating your sprint in a more normal gear), however, the power you produce will be independent of gear selection, whether you're going uphill or downhill, etc. The only thing that really makes a difference is whether you're seated or standing (see http://home.earthlink.net/~acoggan/setraining/index.html, in particular Fig. 2 but also the citation at the end of the article). Since the data in the power profiling table came from standing starts, you therefore might want to also using standing data, although in fact the difference isn't so large as to have a huge impact on your "profile".