The Powermeter Thread

[Alex Simmons/RST]

Frank, I'm not a fan of power meters because after all these years they should be more technologically evolved and the prices more reasonable. But the high-end cycling community is always a sucker for high-priced gear that may or may not have benefits that reflect said retail price.

I hear so much crap from people when I bring up their limitations that discussions like this one always get bogged down in semantics and agendas.

What I don't understand is your attitude towards power meters as a tool. They aren't supposed to make anyone faster per se. They are like speedometers on a car,l a measuring device. They tell you the amount of energy you're expending per ride, per interval, etc.. What's wrong with that?

Which begs the question-what is the difference between gauging improvement via miles or kilometers per hour and watts? I wold think using both in unison would be a great help, and the truth is power meters are here to stay and are not going anywhere.

by and large, measuring power output removes most of the uncontrollable variables that exist when using speed as your yard stick for fitness.

 

[JayKosta]

Has a bit to do with using a PM for measurement and testing you would say?

-------------------------
Certainly agree that for measuring power, a PM is excellent and useful.

In the past several weeks (Winter here now) I have been using an indoor 'exercise bike' (MATRIX) that displays HR, Watts, cadence, speed, etc.
I get motivation from those measurements to keep my desired exertion level, and also the feedback of seeing my power increasing over time.

Perhaps I would get the same motivational benefits from just using 'speed' and perceived exertion, but having the PM and HR is interesting - at least for the few weeks that I've be doing it.

Jay Kosta
Endwell NY USA

 

[sciguy]

-------------------------


Perhaps I would get the same motivational benefits from just using 'speed' and perceived exertion, but having the PM and HR is interesting - at least for the few weeks that I've be doing it.

Jay Kosta
Endwell NY USA

The problem using speed as a metric with a typical indoor trainer is that it is highly influenced by tire pressure, press on force and temperature of hydraulic drag units if one is used. So you really never know for sure if you're putting out more power. In terms of PE, as LeMond always said. "It doesn't get easier you just go faster" . Forty plus years ago I use to judge my winter roller workouts by the size of the sweat puddle I'd accumulate on the rubberized floor in Barton Hall. It was a pretty poor metric but the only one available at the time.

The Matrix may be fancy enough that speed could be used but it still would be more granular than power unless measured to the .01mph.

It sure is nice to see the numbers on an upward trajectory I'm up 28% from my first ride this winter and don't even use PCs

Hugh

 

[FrankDay]

You guys all miss the point. I feel like I am at a cross-fit convention where people have just learned to count and are excited because now they can compare how much they have improved because they can measure how many sit-ups, pull-ups, or push-ups they can do or weight they can lift.

The problem is that I can probably go to 10,000 places where articles (or forum posts) refer to power meters as "the best way" to get better. Examples abound and some have been linked earlier in this thread. Someone without a power meter, but looking to get better, is going to read this stuff and believe it (I suspect plenty already have - many of them reading this thread). Is that the best way to spend $1000 (or more) if the goal is to improve racing outcome? There is simply zero evidence that having or using a power meter in any way enhances outcome in any way. In fact, the evidence suggests the opposite. Otherwise, how does one explain Stefanie Adam. She is an amateur whose bike split last year was 5 minutes faster than the fastest women's pro yet she doesn't use a power meter in training or racing. According to Fergie she must have been surprised by this result because

"…the only way to truly know you are progressing is measuring with a power meter."

Multiple other examples exist.

Anyhow, some here accuse me of fraudulent claims yet they persist in supporting this general belief (because they don't debunk it) that getting a power meter is somehow going to transform training into something more effective than what is done without one. Watching the power change or improve does not mean the power is improving more than if you were not watching it but doing essentially the same amount of work. In fact, it could be counter productive if one should be doing low power base work yet is focused on always increasing power (why does sciguy care if his power is up 28% now in the middle of the winter?) or one increases power by getting into a less aero position, focusing on the power number and ignoring other aspects of improving speed. There is simply zero evidence that having or using a power meter in any way enhances racing outcome. Implying that it does perpetrates the fraud. A power meter may make training more interesting. A power meter may give the geek something to do. A power meter may do a lot of things, but there is no evidence a power meter enhances racing outcome by helping the user gain more power. If anyone has any evidence that it does this should be the thread where it is presented.

 

[CoachFergie]

-------------------------
Certainly agree that for measuring power, a PM is excellent and useful.

In the past several weeks (Winter here now) I have been using an indoor 'exercise bike' (MATRIX) that displays HR, Watts, cadence, speed, etc.
I get motivation from those measurements to keep my desired exertion level, and also the feedback of seeing my power increasing over time.

Perhaps I would get the same motivational benefits from just using 'speed' and perceived exertion, but having the PM and HR is interesting - at least for the few weeks that I've be doing it.

Matrix is a piece of indoor exercise equipment so not really measuring power like a SRM or Quarq.

Same is displaying speed from an stationary bicycle.

Are changes in HR reflecting intensity or dehydration, diet composition, overheating, pretty girls in the gym etc?

Cadence is dependent on the gear and how hard you choose to push the pedals.

So just staring at numbers (some estimated) is not very likely to have an impact on performance.

In much the same way the two "power meter v HR" studies did. Would have got similar results from testing one person watching Family Guy v The Simpsons.

 

[Berzin]

Seriously?

Do you train on the same course every ride and over the same distance and at the same intensity?

And if you did are the weather conditions always exactly the same.

Unless you can honestly say yes to both the only way to truly know you are progressing is measuring with a power meter.

You misunderstood what I said. I asked the question because it's pertinent, but also a bit rhetorical.

Using BOTH speed and power will greatly enhance your data-recording ability, and a rider then can make changes to his training accordingly, more so than with just speed alone, which is what I believe Frank Day is trying to convince us of. Simply by using Power Cranks and checking your speed isn't enough to gauge an improvement using his device. Reading power makes it more objective.

But this isn't true due to the limitations of current power meters. Case in point-

I don't have the level of expertise to get into all the jargon that gets spewed over this debate. My layman's analysis tells me that when collecting data, if you are not able to collect as much as possible, then your collecting methods are incomplete. Therefore, any conclusions will reflect this.

SRM power meters do not measure power of each individual leg. So what you get is half multiplied by two from one leg, the right leg, most people's dominant side. What if you're left-side dominant? There is no reason why power meters can't measure each leg independently. There are issues like leg strength discrepancy, that cannot be evaluated because of this.

I see nothing stopping the current technology from being able to do this, but the vast majority of power meters do not. You can argue all you want about this not being necessary, but to me this lack of an important feature makes current power meters overpriced and overrated.

 

[elapid]

You guys all miss the point. I feel like I am at a cross-fit convention where people have just learned to count and are excited because now they can compare how much they have improved because they can measure how many sit-ups, pull-ups, or push-ups they can do or weight they can lift.

The problem is that I can probably go to 10,000 places where articles (or forum posts) refer to power meters as "the best way" to get better. Examples abound and some have been linked earlier in this thread. Someone without a power meter, but looking to get better, is going to read this stuff and believe it (I suspect plenty already have - many of them reading this thread). Is that the best way to spend $1000 (or more) if the goal is to improve racing outcome? There is simply zero evidence that having or using a power meter in any way enhances outcome in any way. In fact, the evidence suggests the opposite. Otherwise, how does one explain Stefanie Adam. She is an amateur whose bike split last year was 5 minutes faster than the fastest women's pro yet she doesn't use a power meter in training or racing. According to Fergie she must have been surprised by this result because
Multiple other examples exist.

Anyhow, some here accuse me of fraudulent claims yet they persist in supporting this general belief (because they don't debunk it) that getting a power meter is somehow going to transform training into something more effective than what is done without one. Watching the power change or improve does not mean the power is improving more than if you were not watching it but doing essentially the same amount of work. In fact, it could be counter productive if one should be doing low power base work yet is focused on always increasing power (why does sciguy care if his power is up 28% now in the middle of the winter?) or one increases power by getting into a less aero position, focusing on the power number and ignoring other aspects of improving speed. There is simply zero evidence that having or using a power meter in any way enhances racing outcome. Implying that it does perpetrates the fraud. A power meter may make training more interesting. A power meter may give the geek something to do. A power meter may do a lot of things, but there is no evidence a power meter enhances racing outcome by helping the user gain more power. If anyone has any evidence that it does this should be the thread where it is presented.

TROLL ALERT. Nearly everyone, other than you Frank, on this thread has always said a PM is a measuring device. Nothing more, nothing less. You are the only one that persists in thinking that we are saying otherwise.

And, yes, you are a fraud when you claim 40% improvement in power output and cannot support this claim.

 

[Tapeworm]

SRM power meters do not measure power of each individual leg. So what you get is half multiplied by two from one leg, the right leg, most people's dominant side. What if you're left-side dominant? There is no reason why power meters can't measure each leg independently. There are issues like leg strength discrepancy, that cannot be evaluated because of this.

No, you don't, SRM does not work this way (although Stages do). SRMs measure the force applied via the crank. If you unclip one leg or the other you'll still get a power reading

What if you are left or right leg dominant? What's the solution to fix this and why does it actually need fixing?

 

[Berzin]

We've covered the points articulated over power meters not improving performance. I personally think it's one of semantics, but this back-and-forth on this particular issue needs to stop from all sides, regardless if you are for or against.

We moderators have gotten enough complaints about this, so let's all agree to stop it and move on.

At this point, and with all I've read, I think there have been enough misunderstandings to conclude that no one is going to budge, whether their conclusions are based on peer-reviewed physiological studies or if they are purely agenda-driven.

Next post addressing what I just told everyone to stop addressing will receive a deletion of said post and a ban for trolling/baiting. No exceptions.

 

[Berzin]

No, you don't, SRM does not work this way (although Stages do). SRMs measure the force applied via the crank. If you unclip one leg or the other you'll still get a power reading.

Again, arguing semantics for the sake of arguing. Even if you get a reading by unclipping one leg, what possible use could that do for a rider when he's trying to extract data under real world conditions, in this case pedaling with both legs out on the road?

What if you are left or right leg dominant? What's the solution to fix this and why does it actually need fixing?

That should be a personal choice left up to the individual athlete. I'm pointing out that most power meters don't include this feature and the prevailing excuse is "why would one need it"? Well, why wouldn't one need it?

As much data as possible is always preferable to limited data. Go to any research scientist and tell them "do this experiment, and feel free to derive conclusions while leaving something out". You'll get laughed out of the room.

I've gone over leg strength discrepancy here and on other sites. I thought this is something that would seem rather obvious but it's not. If you are the Tapeworm from Weightweenies, you would know what I've written on the subject. It's not worth going over again, for the same reasons as I stated in my previous post.

When opinions are entrenched, it's one thing. But if I feel a certain technology is lacking and say so, all I have to do is vote with my feet and make a purchase not based on price but what I consider functionality, wants and needs, which in the end are all individual perceptions.

 

[Tapeworm]

Again, arguing semantics for the sake of arguing.

Hardly semantics, what you stated was wrong. Most power meters do not take a reading from one leg and double it, the exception being Stages. Most others, SRM, Powertap, Quarq, P2Max etc record the net power output for a given duration.

I've gone over leg strength discrepancy here and on other sites. I thought this is something that would seem rather obvious but it's not. If you are the Tapeworm from Weightweenies, you would know what I've written on the subject.

I am, and I don't. Do you have any links to what you have written?

 

[CoachFergie]

Again, arguing semantics for the sake of arguing. Even if you get a reading by unclipping one leg, what possible use could that do for a rider when he's trying to extract data under real world conditions, in this case pedaling with both legs out on the road?

Not semantics. Strain gauges in the spider of the crank measure the force applied from both legs.

It is with much interest that we watch Team Sky switch from SRM to Stages for competition. Stages only measure the left leg and double the power. If one only pedalled with their left leg with stages it would record no power being produced.

Quarq Elsa and Red and Power 2 Max do record L/R balance while riding.

That should be a personal choice left up to the individual athlete. I'm pointing out that most power meters don't include this feature and the prevailing excuse is "why would one need it"? Well, why wouldn't one need it?

Because the research would suggest that small differences are trivial and large differences are usually injury based. No real need for everyone to measure L/R balance.

As much data as possible is always preferable to limited data. Go to any research scientist and tell them "do this experiment, and feel free to derive conclusions while leaving something out". You'll get laughed out of the room.

Download Golden Cheetah for free and there is data for Africa. My research is on one small part of it and that is barely scratching the surface.

I've gone over leg strength discrepancy here and on other sites. I thought this is something that would seem rather obvious but it's not. If you are the Tapeworm from Weightweenies, you would know what I've written on the subject. It's not worth going over again, for the same reasons as I stated in my previous post.

Separate matter. Perhaps Alex Simmons can chip in about his leg length discrepancy and the L/R imbalance and how this has not limited him from hitting new power PB's.

When opinions are entrenched, it's one thing. But if I feel a certain technology is lacking and say so, all I have to do is vote with my feet and make a purchase not based on price but what I consider functionality, wants and needs, which in the end are all individual perceptions.

With all due respect I think you need to have a look at what different brands of power meter do or don't do.

Bar two I think most agree that they don't and were never intended to improve performance. Only measure it.

 

[sittingbison]

Gentle(wo)men,
I am drawing a line in the sand in this thread. Read what I say VERY clearly before you next post

1) A PM is a measuring device, a PM by itself cannot and will not result in any improvement in cycling performance.

2) A PM is an objective tool to measure performance and hence measure improvement, not cause it or influence it.

3) Any measured improvement is due to training, and not the PM itself.... because of point (1) A PM is a measuring device

Any further claims to the contrary, namely any inference that PMs can somehow improve performance, will from this point be considered trolling and baiting and consequently dealt with harshly.

Don't feed the troll, use the report feature and let a mod (me) deal with it

cheers
bison

 

[Alex Simmons/RST]

Gentle(wo)men,
I am drawing a line in the sand in this thread. Read what I say VERY clearly before you next post

1) A PM is a measuring device, a PM by itself cannot and will not result in any improvement in cycling performance.

2) A PM is an objective tool to measure performance and hence measure improvement, not cause it or influence it.

3) Any measured improvement is due to training, and not the PM itself.... because of point (1) A PM is a measuring device

Any further claims to the contrary, namely any inference that PMs can somehow improve performance, will from this point be considered trolling and baiting and consequently dealt with harshly.

Don't feed the troll, use the report feature and let a mod (me) deal with it

cheers
bison

The power meter is neither a genius nor a motor.

However, power data combined with a good brain can and does result in improved performance that might not otherwise have been obtained, or can result in a performance outcome occurring more quickly than might otherwise have been obtained.

I use power meters all the time and have been for years to improve riders' aerodynamics and check their bike fit is appropriate, especially in locations where access to a tunnel is simply not economically feasible. Immediate performance improvements are available from using power meter data to influence what you choose to do with respect to position and equipment choices. It's instant speed in many cases.

The ability to review season long power data provides a level of helicopter style insight into how someone actually trained, versus what they think they did. I see this all the time with people when I examine their historical data. That insight can be used to change the way they train and lead to better performance that may not have been apparent via other means, e.g. use of a regular training diary alone, or even distance/HR data that can and does mask actual training.

I've seen power meter data to help more rapidly decide on rider order and length of turns in team pursuit, enabling a team to not waste too much time resolving these things and get onto other performance improvement actions.

I've used power meter data to help riders realise and more rapidly correct pacing mistakes in time trialling, resulting in better performance.

There are many ways one can use the data creatively for performance improvement, or to speed up the process of improving performance.

Just because people may not know the way to use the data creatively to drive improvements doesn't mean such methods don't exist.

I agree that someone new to a power meter will likely not have such depth of understanding of how the data can be used, so it's nice that a lot of this experience and knowledge is freely available, or available for not a lot of $ investment, just the time and patience required to learn.

 

[Alex Simmons/RST]

SRM power meters do not measure power of each individual leg. So what you get is half multiplied by two from one leg, the right leg, most people's dominant side. What if you're left-side dominant? There is no reason why power meters can't measure each leg independently. There are issues like leg strength discrepancy, that cannot be evaluated because of this.

I see nothing stopping the current technology from being able to do this, but the vast majority of power meters do not. You can argue all you want about this not being necessary, but to me this lack of an important feature makes current power meters overpriced and overrated.

Your understanding of how the various power meters work is significantly lacking. I suggest you take some time to learn about how they work before continuing to make significant errors on the subject.

As for individual left and right leg measurement, there are various meters available that already do this, although the methodology in how and what they report varies (and as such what you might interpret from knowing the left and right split would vary accordingly).

Whether or not such left-right data provides actionable intelligence is yet to be demonstrated.

I'm open minded on it and over time we will see more good research conducted in this area, but I'd suggest that knowing total output will still be significantly more important than knowing the left-right split.

 

[CoachFergie]

The power meter is neither a genius nor a motor.

However, power data combined with a good brain can and does result in improved performance that might not otherwise have been obtained, or can result in a performance outcome occurring more quickly than might otherwise have been obtained.

I use power meters all the time and have been for years to improve riders' aerodynamics and check their bike fit is appropriate, especially in locations where access to a tunnel is simply not economically feasible. Immediate performance improvements are available from using power meter data to influence what you choose to do with respect to position and equipment choices. It's instant speed in many cases.

The ability to review season long power data provides a level of helicopter style insight into how someone actually trained, versus what they think they did. I see this all the time with people when I examine their historical data. That insight can be used to change the way they train and lead to better performance that may not have been apparent via other means, e.g. use of a regular training diary alone, or even distance/HR data that can and does mask actual training.

I've seen power meter data to help more rapidly decide on rider order and length of turns in team pursuit, enabling a team to not waste too much time resolving these things and get onto other performance improvement actions.

I've used power meter data to help riders realise and more rapidly correct pacing mistakes in time trialling, resulting in better performance.

There are many ways one can use the data creatively for performance improvement, or to speed up the process of improving performance.

Just because people may not know the way to use the data creatively to drive improvements doesn't mean such methods don't exist.

I agree that someone new to a power meter will likely not have such depth of understanding of how the data can be used, so it's nice that a lot of this experience and knowledge is freely available, or available for not a lot of $ investment, just the time and patience required to learn.

Great post Alex.

Only thing I would add is that power measurement is the dependant variable in all this that we measure. The independent variables are the training methods, recovery, programme planning, diet, mindset, position, aerodynamics, application of rules, tactics and other factors.

As a coach the power meter keeps me honest. I can claim am improvement of 40% or 2-3mph but a power meter would show if those claims were real or not.

 

[Alex Simmons/RST]

Only thing I would add is that power measurement is the dependant variable in all this that we measure. The independent variables are the training methods, recovery, programme planning, diet, mindset, position, aerodynamics, application of rules, tactics and other factors.

Oh I get that, but I know for certain that performance can be improved in many ways or improved more quickly with the aid of a power meter data than without.

Some people (e.g. Frank) seem to be confining themselves to a exceptionally narrow paradigm of what constitutes use of power meter data (e.g. as a measure of / guide to exercise intensity), and they need to break those mental shackles (it's a hangover of the training by HR paradigm), or at least recognise that some people are capable of achieving more or more quickly with the aid of such a tool than without.

If you exist in or seek to confine discussion/debate to such a narrow paradigm, then it's no wonder people can't see how improvement can be attained or attained more quickly, as that should come as absolutely no surprise. Hence the Frank line of reasoning fuelled by a silly study which suggests that a rider knowing more precisely how hard they are riding doesn't greatly affect training outcomes if they are following the same basic training plan. Well duh.

That's also why this particular use of the data is the least demanding on power meter accuracy and is why if that's your primary/only field of play wrt power meter data, then you can get along quite well with relatively modest levels of accuracy wrt measuring exercise intensity, even for the most part manage quite OK with perceived exertion or a HR monitor (ignoring psychological aspects of power data, as that can cut both ways).

But like I said, while it's the most common use for power meters, it's still a pretty narrow paradigm.

Scientific proof is demanded by some, well in some cases it actually does exist, for example, aero testing with a (good) power meter and protocols has been demonstrated in the scientific literature and known for a long time to be a valid means of assessing such things and achieving outcomes previously only available in a few wind tunnels. Physics is kinda cool like that.

 

[CoachFergie]

Oh I get that, but I know for certain that performance can be improved in many ways or improved more quickly with the aid of a power meter data than without.

Some people (e.g. Frank) seem to be confining themselves to a exceptionally narrow paradigm of what constitutes use of power meter data (e.g. as a measure of / guide to exercise intensity), and they need to break those mental shackles (it's a hangover of the training by HR paradigm), or at least recognise that some people are capable of achieving more or more quickly with the aid of such a tool than without.

If you exist in or seek to confine discussion/debate to such a narrow paradigm, then it's no wonder people can't see how improvement can be attained or attained more quickly, as that should come as absolutely no surprise. Hence the Frank line of reasoning fuelled by a silly study which suggests that a rider knowing more precisely how hard they are riding doesn't greatly affect training outcomes if they are following the same basic training plan. Well duh.

That's also why this particular use of the data is the least demanding on power meter accuracy and is why if that's your primary/only field of play wrt power meter data, then you can get along quite well with relatively modest levels of accuracy wrt measuring exercise intensity, even for the most part manage quite OK with perceived exertion or a HR monitor (ignoring psychological aspects of power data, as that can cut both ways).

But like I said, while it's the most common use for power meters, it's still a pretty narrow paradigm.

Scientific proof is demanded by some, well in some cases it actually does exist, for example, aero testing with a (good) power meter and protocols has been demonstrated in the scientific literature and known for a long time to be a valid means of assessing such things and achieving outcomes previously only available in a few wind tunnels. Physics is kinda cool like that.

Very well versed on the many things can keep track of using a power meter. Particularly looking forward to spending time in Cambridge (site of our new velodrome) and discussing Alphamantis with David Bowden there. As well as WKO+ 4.0 and some other players in the new metrics of racing and training with a power meter.

 

[sciguy]

Particularly looking forward to spending time in Cambridge (site of our new velodrome) and discussing Alphamantis with David Bowden there.

Fergie,

You'll be very impressed with what Alphamantis can help coaches and cyclists learn and do. Back in the fall of 2012 I was lucky enough to participate in the first Los Angles Velodrome "Aero thing" and came away in awe of what Andy Froncioni and his associates had already developed. Several days rubbing elbows and exchanging ideas with folks considered to be tops in the field made for an especially enjoyable and educational time.

Was David Bowden one of the participants and that event? If I remember correctly there was a Kiwi who attended.

For those folks who belong to the pictures or it didn't happen club, here is one with myself, Robert Chung of "the Chung method" fame and John Cobb.

Recent activity at the LA Velodrome using the technology http://www.slowtwitch.com/Lifestyle/A_California_Aero_Camp_4145.html

 

[acoggan]

Your understanding of how the various power meters work is significantly lacking. I suggest you take some time to learn about how they work before continuing to make significant errors on the subject.

+1

(ten characters)

 

[acoggan]

The power meter is neither a genius nor a motor.

Now there is a PPP! I assume you don't mind me quoting you?

 

[FrankDay]

…However, power data combined with a good brain can and does result in improved performance that might not otherwise have been obtained, or can result in a performance outcome occurring more quickly than might otherwise have been obtained. …

Oh I get that, but I know for certain that performance can be improved in many ways or improved more quickly with the aid of a power meter data than without.

Some people (e.g. Frank) seem to be confining themselves to a exceptionally narrow paradigm of what constitutes use of power meter data (e.g. as a measure of / guide to exercise intensity), and they need to break those mental shackles (it's a hangover of the training by HR paradigm), or at least recognise that some people are capable of achieving more or more quickly with the aid of such a tool than without.

I am not confining myself to anything. Such statements as those highlighted above are commonplace. All I am asking for is the answer to this question. What is the evidence that supports the above statements?

 

[CoachFergie]

Fergie,

You'll be very impressed with what Alphamantis can help coaches and cyclists learn and do. Back in the fall of 2012 I was lucky enough to participate in the first Los Angles Velodrome "Aero thing" and came away in awe of what Andy Froncioni and his associates had already developed. Several days rubbing elbows and exchanging ideas with folks considered to be tops in the field made for an especially enjoyable and educational time.

Was David Bowden one of the participants and that event? If I remember correctly there was a Kiwi who attended.

For those folks who belong to the pictures or it didn't happen club, here is one with myself, Robert Chung of "the Chung method" fame and John Cobb.

Recent activity at the LA Velodrome using the technology http://www.slowtwitch.com/Lifestyle/A_California_Aero_Camp_4145.html

He is the only one I know of in NZ who is directly involved with Alphamantis in NZ. AFAIK no one is or has been doing it in Invercargill on the track there. Funny thing is costs of getting to and using Cambridge may mean I may be better off travelling to Sydney to meet with Alex to get a hands on appreciation.

 

[CoachFergie]

J Sports Sci. 2012;30(14):1491-501. doi: 10.1080/02640414.2012.711487. Epub 2012 Aug 10.

Mechanical work and physiological responses to simulated cross country mountain bike racing.

Macdermid PW, Stannard S.

Abstract
The purpose was to assess the mechanical work and physiological responses to cross country mountain bike racing. Participants (n = 7) cycled on a cross country track at race speed whilst VO2, power, cadence, speed, and geographical position were recorded. Mean power during the designated start section (68.5 ± 5.5 s) was 481 ± 122 W, incurring an O2 deficit of 1.58 ± 0.67 L - min(-1) highlighting a significant initial anaerobic (32.4 ± 10.2%) contribution. Complete lap data produced mean (243 ± 12 W) and normalised (279 ± 15 W) power outputs with 13.3 ± 6.1 and 20.7 ± 8.3% of time spent in high force-high velocity and high force-low velocity, respectively. This equated to, physiological measures for %VO(2max) (77 ± 5%) and % HR(max) (93 ± 2%). Terrain (uphill vs downhill) significantly (P < 0.05) influenced power output (70.9 ± 7.5 vs. 41.0 ± 9.2% W(max)),the distribution of low velocity force production, VO2 (80 ± 1.7 vs. 72 ± 3.7%) and cadence (76 + 2 vs. 55 ± 4 rpm) but not heart rate (93.8 ± 2.3 vs. 91.3 ± 0.6% HR(max)) and led to a significant difference between anaerobic contribution and terrain (uphill, 6.4 ± 3.0 vs. downhill, 3.2 ± 1.8%, respectively) but not aerobic energy contribution. Both power and cadence were highly variable through all sections resulting in one power surge every 32 s and a supra-maximal effort every 106 s. The results show that cross country mountain bike racing consists of predominantly low velocity pedalling with a large high force component and when combined with a high oscillating work rate, necessitates high aerobic energy provision, with intermittent anaerobic contribution. Additional physical stress during downhill sections affords less recovery emphasised by physiological variables remaining high throughout.

 

[Alex Simmons/RST]

I am not confining myself to anything. Such statements as those highlighted above are commonplace. All I am asking for is the answer to this question. What is the evidence that supports the above statements?

I gave several examples, but you choose to ignore them, or is evidence required to prove that the laws of physics also apply to cyclists?