Study on the usefulness of a power over other metrics

[CoachFergie]

Nimmerichter, Alfred , Eston, Roger G. , Bachl, Norbert and Williams, Craig(2011) 'Longitudinal monitoring of power output and heart rate profiles in elite cyclists', Journal of Sports Sciences, 29: 8, 831 — 839.

Heart Rate and power valid measures of intensity over a season but heart rate only up to a point where highly intensive sessions where the VO2max is approached or cardiac drift and cardiac lag make measurement by heart rate imprecise.

Variability of power was inversely related to performance. Backing up countless studies on pacing.

Variability is one of the main advantages of using a power meter as the nature of power application is far more precise than heart rate. The AIS MTB team used to use heart rate to track intensity the a lack of variance in a race led them to believe that steady state training over long durations was appropriate however when they shifted to SRM they found a far greater variance in power and adopted a more interval based approach to preparing for events.

So now there is published evidence that a power meter is a more effective measurement tool than heart rate for intensity and training load over a season.

 

[ergmonkey]

Prepare yourselves for the inevitable misinformation onslaught of Frank Day.

Truth about power meters will not stand!

 

[CoachFergie]

I know, it's quite amusing.

There are also two studies published by Lim this year to discuss.

 

[FrankDay]

Nimmerichter, Alfred , Eston, Roger G. , Bachl, Norbert and Williams, Craig(2011) 'Longitudinal monitoring of power output and heart rate profiles in elite cyclists', Journal of Sports Sciences, 29: 8, 831 — 839.

Heart Rate and power valid measures of intensity over a season but heart rate only up to a point where highly intensive sessions where the VO2max is approached or cardiac drift and cardiac lag make measurement by heart rate imprecise.

Variability of power was inversely related to performance. Backing up countless studies on pacing.

Variability is one of the main advantages of using a power meter as the nature of power application is far more precise than heart rate. The AIS MTB team used to use heart rate to track intensity the a lack of variance in a race led them to believe that steady state training over long durations was appropriate however when they shifted to SRM they found a far greater variance in power and adopted a more interval based approach to preparing for events.

So now there is published evidence that a power meter is a more effective measurement tool than heart rate for intensity and training load over a season.

Huh? You took that study to demonstrate that? Where is the control group? Since all of the subjects had and trained with PM's, if the PM is a superior pacing tool, why weren't the subjects all equally good?

Here is what the abstract says about the what they found: "Significant differences were observed during high-intensity workouts (P < 0.001). Performance improvements across the season were related to low-cadence strength workouts (P < 0.05). The intensity factor for intervals was related to performance (P < 0.01). The variability in power output was inversely associated with performance (P < 0.01). Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals. "

It seems to me that all this study says regarding a PM is that despite having a PM that significant intensity variations in training intensity occur and that these variations are important to outcome. While one might infer that one should be able to reduce variation and achieve better outcome from using a pm as a feedback device from this, this does not prove that it actually happens. This study does not show that getting or using a PM reduces variations (improving outcome) over not having one. As the SportsScientists told me during a back and forth on their site, one of their PhD students actually did that study and found no difference in outcome between PM and HRM - we are all breathlessly awaiting its publication, I am sure. So, the superiority of PM as a training/racing device remains unproven.

Anyhow, thanks for the link.

 

[JayKosta]

From the abstract -

"Performance improvements across the season were related to low-cadence strength workouts (P < 0.05)."

and

"Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals."

- from http://www.informaworld.com/smpp/content~db=all~content=a936417484

So, doing really hard (as was quantified by power output measurement) interval training (low-cadence?) did give improved performance for these riders.

I think that all that this shows is that direct output power measurement is a better indicator of intensity than is heart rate.

Jay Kosta
Endwell NY USA

 

[FrankDay]

From the abstract -

"Performance improvements across the season were related to low-cadence strength workouts (P < 0.05)."

and

"Better performance by cyclists was characterized by lower variability in power output and higher exercise intensities during intervals."

- from http://www.informaworld.com/smpp/content~db=all~content=a936417484

So, doing really hard (as was quantified by power output measurement) interval training (low-cadence?) did give improved performance for these riders.

I think that all that this shows is that direct output power measurement is a better indicator of intensity than is heart rate.

Jay Kosta
Endwell NY USA

I don't think you can say that at all. There is no group to compare to see if it truly is better. As I said, there is a study supposedly in the works that shows there is no difference in outcome between using a PM and HRM.

Further, it is not clear if those who did the highest intensity work were also those who were the most consistent. So, there are three different metrics they found that correlated with better performance. If these all occurred in the same people, which I would suspect for such a small group, we don't know if one of these is much more important than the others or that any of them are just a coincidental finding.

Many will try to use this study as "proof" that a PM is better but from a scientific perspective this hardly constitutes proof although one might infer this. All this study shows is simply a correlation between lower variability and improved performance. (And, more "strength work" and "interval intensity" also correlated with improved performance). This is not evidence that changing to a PM for effort feedback results in lower variability and improved performance. In fact, it says the opposite since all the study members had power meters so there is simply zero evidence in this study that having the PM reduced variability and improved outcome.

One might infer that this could happen from this study but it is not evidence that it does happen, not even close.

 

[MarkvW]

So now there is published evidence that a power meter is a more effective measurement tool than heart rate for intensity and training load over a season.

Even assuming that your conclusion is the correct one, why is it relevant to any kind of modern training program whether or not the powermeter is a "more effective measurement tool" for intensity and training load over the season? Why would you ever want to measure with one metric when you have two metrics at your disposal? Anybody who can afford a powermeter is also going to have a heart rate monitor.

Surely you should use the powermeter data for evaluating intensity and training load over the season, but you'd be missing a lot if you didn't also include heart rate data in your evaluation, and you might be missing even more if you didn't look at the interrelationship between the two (when incorporating things like health, hydration, nutrition, and subjective body sensation into the mix).

Why does it matter that wattage is "more effective" than HR, when anyone with the money will use both? Is there a subtlety here that I am missing?

 

[overgeared]

i can see why somebody might be attracted to writing such a study but no mater how constructed the power-deniers would likely find a way to deconstruct it. imho the benefits of power are deep and wide enough to qualify as common sense, i just look forward to the day when power denial is regarded about as eccentric as toe clips and down tube shifters.

 

[CoachFergie]

Why does it matter that wattage is "more effective" than HR, when anyone with the money will use both? Is there a subtlety here that I am missing?

If one took a trip to the 'wattage' list you would find many with a power meter never use the heart rate strap.

 

[MarkvW]

If one took a trip to the 'wattage' list you would find many with a power meter never use the heart rate strap.

Wow! Thanks. That explains it.

 

[FrankDay]

Wow! Thanks. That explains it.

Explains what?

 

[CoachFergie]

Wow! Thanks. That explains it.

You're easily satisfied.

I still collect HR data. Many don't. But mostly I collect HR data to point out that it doesn't really tell us much. We had our National Road Race champs and the variability of HR in the road race was far lower than wattage. Wattage being a far more sensitive measure of the effort in the race. A far more sensitive coaching tool to work with riders to reduce that variability in power so they can race more effectively and we can structure training sessions to reflect the demands of specific events.

 

[brianf7]

If one took a trip to the 'wattage' list you would find many with a power meter never use the heart rate strap.

In the end you need to have both and be able to comapare them so you see what your Hr is at what power over the season.
otherwise its all useless data telling you what you should already know .
I am having a good day i am in form and if you dont know that from the perceived method its no use to you.

What you need to know is . is power improving for given effort if not you are ready to rest.

Training is like a peice of toast when its brown its done and when its black is Bug!!!. so best slightly under done.

 

[CoachFergie]

In the end you need to have both and be able to comapare them so you see what your Hr is at what power over the season.
otherwise its all useless data telling you what you should already know .

Nonsense.

If I get to the end of the season and I can hold 10 watts more for 60min than at the start then I know I have improved.

If I can hold 5 heart beats more for 60min than at the start that tells me nothing.

I am having a good day i am in form and if you dont know that from the perceived method its no use to you.

Can't be measured so how can you track any improvement?

 

[MarkvW]

Watch out for what you wish for!

i can see why somebody might be attracted to writing such a study but no mater how constructed the power-deniers would likely find a way to deconstruct it. imho the benefits of power are deep and wide enough to qualify as common sense, i just look forward to the day when power denial is regarded about as eccentric as toe clips and down tube shifters.

On the one hand, everybody who denies the advantages of power is a potential opponent--so why look forward to the day when potential opponents get stronger? On the other hand, prices will drop when more people buy powermeters.

 

[MarkvW]

Nonsense.

If I get to the end of the season and I can hold 10 watts more for 60min than at the start then I know I have improved.

If I can hold 5 heart beats more for 60min than at the start that tells me nothing.


Can't be measured so how can you track any improvement?

The ability to "hold more" heartbeats might be an indicator that you are improving in your ability to clear lactic acid. That, in turn, could suggest that your tempo riding has improved and that your training has been successful in that regard. That information could be helpful in planning your next blocks of training.

Further, if you have to hammer your heart to eke out those ten more watts, your performance gain is not as dramatic as it would be if you got those ten watts more without the extra heartbeats. The heartbeat information, coupled with the wattage information, can give you a better indication of the magnitude of your performance gain.

 

[CoachFergie]

The ability to "hold more" heartbeats might be an indicator that you are improving in your ability to clear lactic acid. That, in turn, could suggest that your tempo riding has improved and that your training has been successful in that regard. That information could be helpful in planning your next blocks of training.

Further, if you have to hammer your heart to eke out those ten more watts, your performance gain is not as dramatic as it would be if you got those ten watts more without the extra heartbeats. The heartbeat information, coupled with the wattage information, can give you a better indication of the magnitude of your performance gain.

I have several riders (myself included) who have seen gains in power at various thresholds while heart rate has dropped as much as 15 beats.

That high heart rate may be an indication you are dehydrated, overheating, have been consuming a high CHO diet, quite fancy the lab assistant testing you, are apprehensive about the results of testing or a variety of other matters.

 

[Tapeworm]

@MarkvW

Or lactate even

Or maybe your HR is higher due to increased arousal for example. I've had my HR at near my all time max hr when not even turning the pedals, though this could be from sheer terror from the joys of going downhill on a mtb... but no work being done.

I am not against HR data being collected but for me it is a point of interest rather than something to base training off.

A friend of mine suffered mild bouts of sub-ventricular tachycardia, heart rates of over 230 BPM, strangely the watts didn't track with hr...

 

[MarkvW]

Explains what?

Why the dialog is powermeter vs. heart rate rather than how to interpret HR and powermeter data together.

 

[CoachFergie]

Why the dialog is powermeter vs. heart rate rather than how to interpret HR and powermeter data together.

What does the heart rate tell you and why do so many who train with a power meter (assuming they are data collecting types and came from heart rate) not bother with heart rate?

 

[Vegan Dave]

You're easily satisfied.

I still collect HR data. Many don't. But mostly I collect HR data to point out that it doesn't really tell us much. We had our National Road Race champs and the variability of HR in the road race was far lower than wattage. Wattage being a far more sensitive measure of the effort in the race. A far more sensitive coaching tool to work with riders to reduce that variability in power so they can race more effectively and we can structure training sessions to reflect the demands of specific events.

HR doesn't tell us much? Crikey... Makes me wonder why it was ever used in the first place! /sarcasm

It's probably not terribly useful in a race scenario, but HR is still essential for training. One simple example is response to intervals. If HR is too low during the effort (and recovery during the rest interval is appropriate), it's probably a sign that the rider needs to go too harder/up the wattage.

It's also essential in determining if recovery between intervals is sufficient, or if over-training is occurring.

Power tells you what you're doing. HR tells you your body's response.

Any 'coach' who tells you to train with just power and ignore HR should be given a wide berth.

 

[acoggan]

Power tells you what you're doing. PE tells you your body's response.

I fixed your post for you.

 

[acoggan]

Why the dialog is powermeter vs. heart rate

In Frank's case, it is apparently because he hopes that people will spend their money on his product rather than a powermeter.

rather than how to interpret HR and powermeter data together.

If you know power, then at best heart rate is redundant but at worst it is misleading.

 

[CoachFergie]

HR doesn't tell us much? Crikey... Makes me wonder why it was ever used in the first place! /sarcasm

In the nineties I read over 50 different studies on heart rate training and each had a different conclusion. No general conclusions could be drawn. Didn't stop the onslaught of heart rate training guides with no real physiological basis. Mind you 15 years later as long as you can find some Pro rider that uses a heart rate monitor this passes as sufficient evidence

It's probably not terribly useful in a race scenario, but HR is still essential for training.

Essential?

One simple example is response to intervals. If HR is too low during the effort (and recovery during the rest interval is appropriate), it's probably a sign that the rider needs to go too harder/up the wattage.

And power alone doesn't tell you that without being affected by cardiac lag (short efforts) or cardiac drift (longer efforts)?

It's also essential in determining if recovery between intervals is sufficient, or if over-training is occurring.

Power tells you if recovery is sufficient and the Performance Manager in Training Peaks is a far more effective tool for long term tracking of overtraining.

Power tells you what you're doing. HR tells you your body's response.

Only problem is you have no idea why heart rate is what it is. While you either can do the wattage or you can't.

Any 'coach' who tells you to train with just power and ignore HR should be given a wide berth.

Any coach who doesn't have enough understanding of why HR is such a poor metric compared to power should be given a wider berth.

 

[oldborn]

Interesting study which IMHO really tell us nothing new, lot of wrong protocol in that study.

When study shows us that group (trained athletes, same age, 3 months of study) who trained with PM (and tailor their needs and overload for specific event) is faster and better in 20km TT for 1 minutes then control group who trained without PM, I would be first one in the line

Since then we can just speculate, of course there is some benefits from PM, but claiming that PM is Alpha&Omega is just marketing and expensive one.

Far more better solution is to hire a coach for 2 years for that money, i am giving my right arm that we should benefit far more.