The Powermeter Thread

[Retro Trev]

Ah so he is. Bad troll!!!

I don't forum as much as I did. See he was banned from TT forum and in the Sock Puppet stage on Bike Radar.

What exciting lives some people lead.

I take offence to being called a troll. If you do not like my views argue like a man - do not resort to name calling or try to undermine the person.

Several people have been accused of being me on Bike Radar Forum.

I am BigFatBloke on Bike Radar Forum and I have confirmed I am Trev.
Yes I am banned from timetrialling forum for persistently questioning accepted dogma.

 

[CoachFergie]

You don't get banned for having a difference of opinion. Otherwise Frank and I would have been kicked out years ago. He is banned from Slowtwitch. You're going in my ignore file so troll away, won't affect me.

 

[Retro Trev]

You don't get banned for having a difference of opinion. Otherwise Frank and I would have been kicked out years ago. He is banned from Slowtwitch. You're going in my ignore file so troll away, won't affect me.

Good - all you do is spout Coggan's dogma. You have no original thought.

 

[Retro Trev]

So does Yates think TSS and Performance Manager is rubbish or does he think they don't know how to use it at Sky?

Not impressed with the Team Sky management

Yates reveals that he is not impressed with Team Sky’s current management and that the only member of the team set-up he is still close to is sports director Nicolas Portal.

“To be brutally honest, there is no one at Sky who knows much about bike riding."

“In general, this year especially, the guys running the team don’t know enough about bike-riding and a lot of the riders went into the Tour overtired. They are made to race too much, too long, too hard.”

Yates revealed he has had offers to join other teams but seems happy to have stepped away and because he believes Chris Froome will dominate the sport for years to come.

 

[sittingbison]

Calm down you lot. Let's give accusations of trolling and attacking the poster a rest shall we.

Capiche?

cheers
Bison

 

[FrankDay]

Your system is flawed. It is nothing more than a watts addition system. It is just plain stupid to think you can describe training load and the stress it imposes on an individual with a number which is derived from wattage alone.

While I would agree with you that the system is flawed and imperfect it is not, in fact, totally without merit as it is an attempt to improve training monitoring and to give a metric to allow comparing training load between athletes.

While it has not been scientifically validated pretty much nothing in coaching has been scientifically validated. About all that has been scientifically validated is if you train more you will generally get better. With just about everything else coaches are guessing as to what is best based upon their own limited and biased experience. But, these people who believe in these systems are affronted when someone points out that the king isn't wearing any clothes.

The TSS system tries to fill a need. It does so imperfectly (just as the power meter tries to do for monitoring training effort) but I challenge you to point to something better. The problem isn't with the TSS system but in how it gets used and in how it gets over-hyped by advocates.

 

[hiero2]

You don't get banned for having a difference of opinion. Otherwise Frank and I would have been kicked out years ago. He is banned from Slowtwitch. You're going in my ignore file so troll away, won't affect me.

Coach, this gave me a laugh for sure. Yup, you are right. You and Frank have so much to talk about, sometimes other folks get kinda intimidated in here. But you guys have both worked to keep the volume tolerable, and that effort is appreciated.

 

[CoachFergie]

No model is perfect. In cycling far too many variables to control for. I only use the PMC to tell me where a rider is currently as I do with other metrics like FTP or Max Mean Powers. But it does not absolve the rider, sport scientist or coach from looking at other metrics outside of power meter data in the quest for cycle racing or cycling fitness success.

 

[CoachFergie]

Garmin Vector after 5 weeks of use...

http://www.dcrainmaker.com/2013/09/garmin-vector-review.html

 

[CoachFergie]

Includes sections on the effect of riding in the peloton on power output.

Peloton phase oscillations

Hugh Trenchard

Chaos, Solitons & Fractals
Volume 56, November 2013, Pages 194–201

http://www.sciencedirect.com/science/article/pii/S0960077913001574

Highlights

•The nature of mass-start bicycle racing is explained; peloton is defined.
•A peloton is a complex system; outlined are its system properties and principles.
•Two equations define coupling principle in pelotons.
•An equation is given as the basis for a computational algorithm.
•Peloton density oscillations and phase regime for oscillations are modeled.

Abstract

A peloton may be defined as two or more cyclists riding in sufficiently close proximity to be located either in one of two basic positions: (1) behind cyclists in zones of reduced air pressure, referred to as ‘drafting’, or (2) in non-drafting positions where air pressure is highest. Cyclists in drafting zones expend less energy than in front positions. Qualitative observations of pelotons indicate oscillations between two primary phases. The first is a high density, low speed/power output phase. The second is a synchronized, low density, high speed or power output phase. Pelotons are observed to oscillate between phases, and mixed phases occur. Principles determining the first phase are coupling due to the energy savings of drafting, collision avoidance, and continuous passing. Principles determining the synchronized phase are similar, except that minimal passing is observed in this phase as cyclists approach maximum sustainable outputs. Phases self-organize as cyclists proceed through output thresholds, while strategic and tactical considerations are secondary. A computational simulation with an algorithm combining a coupling ratio, passing time, and constraints on angles of alignment, separation and cohesion (flocking rules), demonstrates phase oscillations.

 

[sciguy]

The cost of a crank based power meters from Power2Max just dropped today as announced at Interbike. Good news for those shopping for a power meter. Who says that competition doesn't influence price?


Prices of all power meters are lower - the $899 for the Gossamer stays, the Rotor 3D is now $1,099 (previously $1,349), 3D+ 1,249 (previously 1,449)
We ship all power meters for free in USA and Canada
We are proud to announce a partnership with Praxis Works to bring the best shifting chain rings
We continue to serve all 50 US States free of tax.

Hugh

 

[CoachFergie]

With the lowering of Powertap prices earlier in the year it is a good sign.

 

[CoachFergie]

Because I am slow and fat I am content using an old wired SRM that I brought from Bermuda of all places. It was a Dura Ace model and had 52 x 39 rings so even with a 29t I struggle on our steeper hills. Fortunately a track sprinter I work with who has a track SRM decided to get one for his road bike and ended up buying a compact model from the US. I suggested we swap so I could have a compact and he could have the uber stiff Dura Ace cranks.

Big challenge with any SRM is fitting the magnet so it is picked up by the crank. A bigger challenge with a compact with a smaller contact area and I ride a Pinarello which has an oversize BB area. Checked the magnet was picking up the cranks which it was. In the end filed the magnet down as much as possible to get it to fit close enough to pick up and checked with a zero-offset around the pedal stroke to make sure it was picking up all the way round.

Finally did a static calibration with a known weight. Good thing too as the slope on the crank of 22.3 needed to be changed to 23.9. Had I not checked this it would have read 8% high. Good for my ego but not good for the measurement process.

Used this site to work out the correct slope...

http://www.cyclingpowerlab.com/PowerMeterCalibration.aspx

You can see the weight I use for the static calibration. All I need to do is hook the weight on the pedal and roll the bike backwards to get a reading. A local engineer made it for me and I used the scales at the post office to confirm the weight (20.22kg).

Works fine now, easy peasey when you follow simple instructions and use a bit of ingenuity. Next step is to get my CTL over 30

 

[CoachFergie]

Gilbert's power from the World Champs RR last week. Giving us real insight into the demands of professional racing.

 

[CoachFergie]

More Alex Simmons Gold....

Increased power meter use at Kona!

http://alex-cycle.blogspot.com.au/2013/10/power-meter-usage-on-rise-at-kona.html

 

[FrankDay]

Sam Gyde's power files from the Ironman World Championships on Saturday. Sam is an amateur but had the 5th fastest bike split (including the pros) for the day (remember, in Ironman pros and amateurs ride the same course separated by 30 minutes so conditions are comparable). And, remember, this was done after swimming for 2.4 miles and knowing that after this effort he would be asked to run a marathon (which he did in 3 hrs). Total time on the course 8:45. Compare to Gilbert's file above to get a sense of the effort put in by elite triathletes compared to elite cyclists. Comparable I would say.
http://i40.tinypic.com/116jcqg.jpg

 

[CoachFergie]

More Alex Simmons Gold....

Increased power meter use at Kona!

http://alex-cycle.blogspot.com.au/2013/10/power-meter-usage-on-rise-at-kona.html

Huge increase in the number of people using Quarq's and already 23 people using the Garmin Vector.

In NZ the importer approached me direct to sell Quarq's recognising that when marketing such a specific, high ticket and woefully misunderstood product it pays to have people selling them how understand what they can and can't do.

I was also involved with Power2Max in NZ when they started selling them here as a technical consultant.

Just wish SRM saw the potential in involving coaches in the Sales process.

Thanks for publishing those numbers Alex.

 

[CoachFergie]

Coach - Athlete interaction using Training Stress Scores and the Performance Management Chart.

http://www.ironman.com/media-librar.../thad-beaty-training-peaks.aspx#axzz2hmurZ9jr

 

[FrankDay]

Coach - Athlete interaction using Training Stress Scores and the Performance Management Chart.

http://www.ironman.com/media-librar.../thad-beaty-training-peaks.aspx#axzz2hmurZ9jr

I kept hearing the word science. Perhaps you could point me to some of the science that goes to what they were talking about.

Anyhow, it would have been nice if one of them had put forth what the numbers predicted for his race so we could compare but, it seems, they forgot to mention that. Too bad.

 

[CoachFergie]

I kept hearing the word science. Perhaps you could point me to some of the science that goes to what they were talking about.

Anyhow, it would have been nice if one of them had put forth what the numbers predicted for his race so we could compare but, it seems, they forgot to mention that. Too bad.

Hardly going to fully cover the entire process in such a short clip.

Here is a paper coming out on the quantifying training load issue...

http://link.springer.com/article/10.1007/s00421-013-2745-1

or this paper by McGregor...

http://www.ncbi.nlm.nih.gov/pubmed/19910822

There are some other papers coming out that use Training Stress Scores that were presented at either ECSS or ACSM. All based on the impulse response model.

 

[FrankDay]

Hardly going to fully cover the entire process in such a short clip.

Here is a paper coming out on the quantifying training load issue...

http://link.springer.com/article/10.1007/s00421-013-2745-1

Thanks. At least there is something. From the above: "These findings showed that each of the training load methods investigated are appropriate for quantifying endurance training dose and that submaximal HR and HRV may be useful for monitoring fitness and fatigue, respectively." My understanding is the TSS training peaks uses for cyclists comes from power numbers and not HR. If not, can you give me the argument for knowing power again, at least as it goes to this issue? If so, is there a similar correlation for following power and is it better than knowing HR and HRV?

 

[CoachFergie]

Thanks. At least there is something. From the above: "These findings showed that each of the training load methods investigated are appropriate for quantifying endurance training dose and that submaximal HR and HRV may be useful for monitoring fitness and fatigue, respectively." My understanding is the TSS training peaks uses for cyclists comes from power numbers and not HR. If not, can you give me the argument for knowing power again, at least as it goes to this issue? If so, is there a similar correlation for following power and is it better than knowing HR and HRV?

Power is a direct measure of work performed in cycling. The only thing that changes power on the meter is the riders input. HR and HRV are measure's of the response to that work performed. But other factors will influence HR and HRV like heat, hydration or glycogen levels. In much the same way that wind, friction or gravity will affect the speed one sees on a cycle computer.

 

[FrankDay]

Power is a direct measure of work performed in cycling. The only thing that changes power on the meter is the riders input. HR and HRV are measure's of the response to that work performed. But other factors will influence HR and HRV like heat, hydration or glycogen levels. In much the same way that wind, friction or gravity will affect the speed one sees on a cycle computer.

That sounds nice. Where is the scientific correlation that supports what you say/imply? Further, power is really only the useful result of the riders energy expenditure and may have less bearing on fitness and fatigue than the physiologic metric of HR and HRV. The studies you referenced were done on runners where power is not possible to measure and they show a reasonable correlation between HR and HRV to fitness and fatigue. What is needed is a study showing that in cyclists HR and HRV works as well but that power is a better metric to follow, which everyone seems to believe but has yet to be demonstrated, AFAIK.

 

[CoachFergie]

Where is the scientific correlation that supports what you say/imply?

http://link.springer.com/article/10.2165/11317780-000000000-00000

Further, power is really only the useful result of the riders energy expenditure and may have less bearing on fitness and fatigue than the physiologic metric of HR and HRV.

Energy expenditure is a measure of work. The ability to do more work is a factor in sports performance. HR and HRV are a measure of the response to performing work. But you have no way of knowing what other variables like heat, glycogen, psychological stress are having on heart rate. If you have the choice why not measure the actual work performed.

The studies you referenced were done on runners where power is not possible to measure and they show a reasonable correlation between HR and HRV to fitness and fatigue.

Yes, also easier to measure outcomes in running.

In cycling there it is harder to measure outcomes. Therefore harder to show if any intervention had an influence on the end result. Also hard to say that Chronic Training Load or Training Stress Balance management lead to an increase in Power in 250km Road Race because racing is not decided by the person with the most power.

But as outlined in the video one can use this information to guide the tactical process. I am able to inform my riders that their Chronic Training Load is high and because we have managed their fatigue levels their Training Stress Balance is in the Positives they can ride maximally in an event.

I might see a low CTL and suggest a rider get more miles in to raise it. I have seen riders come back from surgery or crashes and not get their CTL back up. Their Mean Maximal Powers may have returned but without the base fitness they struggle to recover from hard sections in races or between races.

What is needed is a study showing that in cyclists HR and HRV works as well but that power is a better metric to follow, which everyone seems to believe but has yet to be demonstrated, AFAIK.

The way you word that is creating another Strawman (no surprises there) but yes that is where I am focusing my efforts. For my junior athletes who have far more basic things to learn that riding and racing with a power meter I do use HR data recorded from a Garmin which is easily uploaded to to TrainingPeaks and this does determine a HR based Training Stress Score or I can use Golden Cheetah (2.0) to see TRIMPS.

With the issue of physiological measures not showing the full picture of cycle racing outcomes (R2 for VO2max, Efficiency and Fractional Utilisation of VO2max is 0.7 in time trials) I might start with comparing the Performance Manager and time trial racing outcomes.

Martin Buchheit is doing some cool work on HRV in Soccer Players and we had a chat recently and shared the issues of doing work with high performing athletes with so many variables influencing performance and so many more influencing outcomes making measurement a nightmare.

 

[CoachFergie]

Practical applications of riding and racing with a Power Meter

http://www.youtube.com/watch?v=Mn5go5zeM8U&feature=youtu.be