I'm not going to bother arguing with you. You may well be right, but most people will just assume you are trashing the study, and those that did the study, because you dont like their results or conclusions.

It isn't as if you don't have a vested interest and your opinion is hardly unbiased.

Crikey, motivation to Troll a bit low today Trev? Are you starting to get the feeling your efforts are in vain. That no one here actually believes anything you say, and your half assed (arsed for fellow Oceania folk) thought experiments show little thinking at all. Perhaps it's just a slow day at Troll Central. Get a good nights sleep and we expect a better effort tomorrow.

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Hamish Ferguson: Cycling Coach

I have no vested interests.

There is also no point in arguing with me, because the authors' own data show that I am right.

Of course, even if you did argue with me, no one would listen to you.

You never have argued Trev, only trolled.

Sound arguments require logical reasoning and/or valid insight or evidence, neither of which have you ever displayed.

Most people just assume you're a troll with a weird personal vendetta.

I suggest being very careful when throwing around such false accusations.


Your comments are a disgrace, should be retracted and an apology provided.

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http://www.cyclecoach.com
http://www.aerocoach.com.au

You are listed under "Coaching Solutions" on the Stryd website:
https://www.stryd.com/partnership

It may be that you weren't aware of that fact, but you can surely see why Trev might think you have a vested interest in defending Stryd.

A presentation by Andrew Coggan on the Stryd website.

https://blog.stryd.com/...ng-runningwithpower/

I don't really approve of Trev's manner of posting, in general, and I can certainly understand people perceiving him as a troll. He has an emotional reaction to things, and often posts with strong emotions fuelling him rather than calm logic. And he's not a scientist, so isn't good at articulating his thoughts in a rigorous manner. But if the reader understands all that, and is willing to make the effort to understand where he's coming from, rather than being overly focused on how he has conveyed that, which often isn't great, he does actually often have some valid insights.

His post in this thread is a good example. I read it, and knew that there must be a valid reason for him saying what he did, so went to the Stryd website to find it. Now, I think he should have posted a bit differently and explained why he was saying it, but in his mind, he would have read Andy's post, recalled content linking him and Stryd in the past, got angry, and posted. That's not trolling, even if his style of putting it across could have been better.

Obviously that is a mistake, since I am a scientist, not a coach.

Now I used to consult for Stryd (and Adidas, the English Institute of Sport, Velicious Software, etc.), but I dropped all of those commitments a couple of years ago.

No, Trev is just a troll who wants attention.

Assumes a commercial relationship. Which in such a minor field in the big scheme of things very rarely exists.

Also notable that in the "coaches" section it states "coaches and exercise physiologists".

So, really reaching there Trev. You get that good nights sleep and try and lift your game in the morning ;)

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Hamish Ferguson: Cycling Coach

Trev's behaviour has been consistently troll-like for years. He does not ask genuine questions, nor is he interested in genuine answers. He maintains a personal vendetta and he devalues public discussion and debate on topics such as this.

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http://www.cyclecoach.com
http://www.aerocoach.com.au

A presentation by Andrew Coggan on the Moxy NIRS monitor:

https://www.google.com/...dtJrlR5uKgkfHobzANhS

Never was a paid consultant for Moxy, though.

IOW, I have never been afraid to share my opinion, often for free (much to my wife's consternation).

What "outburst"? I pointed to a paper that would presumably be of interest to at least some here, and stated my opinion of it. If you want to debate the matter, I suggest you read the paper* and offer a counter-argument. Otherwise, you are just wasting everyone's time.

*Don't go complaining to me if you cannot access the paper, as I am not the one responsible for that.

What, you mean like this?

https://www.ncbi.nlm.nih.gov/pubmed/29547495

Sadly, there are numerous papers published these days that really shouldn't be (not talking about Whitfield et Al. here). However, only a crank would spend inordinate amounts of time writing dozens and dozens of letters-to-editor about them. Most productive scientists are too busy chasing funding to waste their time that way.

If anyone wants to read the full paper, the authors have now uploaded it to researchgate.net:

https://www.researchgate.net/...Recreational_Runners

Dear Andrew,
by any chance, have you requested the raw data to produce a non normalized version of figure 1 (by speed) and table 2 (by weight)?

Cheers,

Guido

Dr. Coggan ,
If you were to design your perfect study to test whatever you would like regarding Stryd/running power, what would you test, why, and what would be your design? Simply curious.

Many thanks, Chris

No, as I have neither the time nor the energy to try to clean up the authors' (and reviewers' and editor's) mistakes.* If I had been a reviewer of the paper, though, those are the data I would have asked to see.

*Note that this study used the original Stryd chest strap, which they stopped making 2 y ago. It's therefore really a moot point anyway.

Stryd has multiple PhDs working for them, and being in the private sector, far greater resources than the typical scientist (especially in biomechanics, where, e.g., NIH funding is uncommon). For example, while many labs might spend years pining for a $60k force plate treadmill, Stryd simply said, the heck with that, and built their own in house (and with specs that put other lab-grade commercial offerings to shame).

The bottom line is that they have already done just about any test I could propose, such that I don't need to wait around for the sports science community to play catch-up before concluding that the device (especially the 2nd gen footpod) does what it claims to do.

The real question is therefore not whether the data are accurate and precise, but what can you do with it.

Data are accurate: I would say yes and I use a Stryd for the only purpose of getting a relevant instantaneous running speed (I am curious about leg stiffness too, but not much data available about its accuracy with a Stryd).

However, I disagree about the use of the term "running power": this is NOT (mechanical) power that Stryd indicates and they explain it in their white paper. Hence why say Garmin footpod gives way different power values. They aim for a tinkered variable correlated with oxygen consumption and it seems to work in some conditions (no wind, no slippery ground surface, no bodyweight weight change...), but I repeat this is NOT mechanical power even if they try to surf on the cycling power fashion wave...

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- Antony Costes -
PhD in Biomechanics / Professional Triathlete (9 pro wins)

"If you cannot measure it, you cannot improve it."
Lord Kelvin

It is when you are running on the flat.

As for Garmin providing higher values, that is not because Stryd adjusts the up/downhill data (based on published studies) to better reflect metabolic cost. Rather, it is because Garmin simply defines power differently (for Stryd, it is the gross external power, i.e., the work you do against the environment divided by time).

Personally, I would have just reported the latter, and let my customers learn that producing the same power may feel differently when running up or down hills. Either that, or just present estimated VO2, and not have to deal with all the misconceptions/criticisms/comparisons with cycling.

On a treadmill that is probably true, yes. How does it account for wind or change in terrain though, that isn't as easy to mimic on a treadmill. I haven't used a running power meter, but everything I have read about cycling power meters says that it either measures power (usually good, but expensive) or estimates power (usually not good, but cheaper)

Out of curiousity, why did Stryd build their own treadmill? Team Sky don't build their own buses or trainers, they buy the best available to them. Are they really more capable of making a top treadmill than specialist companies? If so they should sell them too!

True, normalizing for speed was a detrimental obfuscation affecting one of the three goals of the study. It still presents some other usefull conclusions.

In the end any device like this will always be limited by its sensors and algorythms when inferring a metric. It will most likely rarely be right in the absolute, but can be fairly ok in relative terms for individuals under certain conditions. That might be sufficient, although running introduces more variables with greater variability across individuals than cycling when trying to estimate power. I don't think the greatest value in Stryd resides in effort management, but in directly measured efficiency improvement metrics.

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Pain is inevitable. Suffering is up to you.