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Re: DCRainmaker preview of Stryd running power meter [dado0583] [ In reply to ]
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dado0583 wrote:
mamilner26 wrote:
I am interested in this product, however I will wait to see what others have to say before purchasing.


I've got some via the coaches package. Some feedback:
  • The devices I gave out to some people I coach don't get used properly. They are not techy and didn't get excited about the data like I hoped they would so the other points relate to my experiences. I think when power is supported by watches while in run mode, it will be more easily digestible.
  • I've been recording data since August and find it interesting looking at the power data. Most of the time I train via heart rate or pace and don't feel like I NEED power. Given you can't cover as much ground on foot as by bike it normally means I'm running on the same terrain most of the time so I can compare overall training progress using pace @ heart rate.
  • My run test (4x1 mile all out effort) is on a flat path with little risk of injury with another person so I can do it outside. I wouldn't feel comfortable about doing a bike test outside as I would be more susceptible to riding into the back of a car or something.
  • I actually found then when I was running on sand the Stryd did seem to incorporate the terrain (i.e. watts on sand were worth less than watts on asphalt). I didn't do any specific testing to prove, it was just my perception so may be wrong.
  • I have a run test I did the other week and wish I had the power data to look into it (it was recording but the power was incorrect due to a firmware bug). I ran 4 miles (with a recovery) at exactly the same average heart rate but the times were very different (one I ran 5:28 and another at 5:57). This seemed like a huge difference and felt like power would have given me a chance to try and digest it. The bug is fixed now, so hoping to understand a bit more about pacing from the power data in future.

I agree with this completely. I would consider myself as quite techie, but running in bike mode (even with pace added via the Stryd Garmin ConnectIQ app on 920XT) just becomes a pain for managing data. I have swim, bike, run workouts scheduled in training peaks. I have my devices download to Garmin connect and then automatically pushed to Training Peaks. All Runs come up as Bike workouts in both GC and TP. I need to go into TP delete the Stryd run, manually change the GC file from bike to run, download the corrected GC file to my desktop, and then upload the corrected file to TP. Unfortunately, just changing TP file from bike to run doesn't fix all issues that are created by having a run file incorrectly loaded as a bike file.

By worth less, do you mean that a run at the same power is slower?
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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"... if my understanding of how they are calculating power is correct..."


If your understanding of how power is calculated is correct, would the Garmin HRM run device (or device coupled with appropriate Garmin watch) be basically only a firmware update away from providing power? The accelerometer is already being used to provide stride frequency, vertical displacement, and ground contact time.
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Re: DCRainmaker preview of Stryd running power meter [mamilner26] [ In reply to ]
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mamilner26 wrote:
I am interested in this product, however I will wait to see what others have to say before purchasing.


My 2 cents as someone who has a Stryd but only used it twice - until Garmin supports power in "run mode" I don't see myself using it any more. It's really interesting to see the power numbers during a run, but being in "bike mode" definitely has its drawbacks. Additionally, the file uploads to TP as a ride and makes TSS inaccurate (unless your critical run power just so happens to exactly match your FTP) even after you change it to a run so you really have to manually enter your stats as a run, then you lose all the analytics in the expanded view (charts, etc.)
Last edited by: The1Jacker: Dec 23, 15 7:20
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Re: DCRainmaker preview of Stryd running power meter [The1Jacker] [ In reply to ]
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The1Jacker wrote:
mamilner26 wrote:
I am interested in this product, however I will wait to see what others have to say before purchasing.


My 2 cents as someone who has a Stryd but only used it twice - until Garmin supports power in "run mode" I don't see myself using it any more. It's really interesting to see the power numbers during a run, but being in "bike mode" definitely has its drawbacks. Additionally, the file uploads to TP as a ride and makes TSS inaccurate (unless your critical run power just so happens to exactly match your FTP) even after you change it to a run so you really have to manually enter your stats as a run, then you lose all the analytics in the expanded view (charts, etc.)

Fixed as of today, apparently (note that I don't use TP, so may not know what the heck I'm talking about!):

http://club.stryd.com/...o-trainingpeaks/1385
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Re: DCRainmaker preview of Stryd running power meter [J_R] [ In reply to ]
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J_R wrote:


"... if my understanding of how they are calculating power is correct..."


If your understanding of how power is calculated is correct, would the Garmin HRM run device (or device coupled with appropriate Garmin watch) be basically only a firmware update away from providing power? The accelerometer is already being used to provide stride frequency, vertical displacement, and ground contact time.

As with all such things, the devil is in the details.
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
davearm wrote:
Andrew Coggan wrote:
I can't see a running power meter having a significant impact on how people actually train and perform.

In an IM race, I know...

I should target a NP of 68-70% of my FTP
I should target a VI of around 1.05
I should keep MaxP ~ FTP

Intuitively, all of these same concepts of optimal average and maximum power production, and variance, seem like they would apply to running as well.

Specifically, it would stand to reason that a robust running power meter would answer the question of how fast an IM racer should run up a hill, just as a power meter already does for the same athlete on his bike. Since there is an optimal power output when climbing a hill on the bike course, surely there is a corollary for climbing a hill on the run course.

Given that, I don't at all understand why you don't see value in a device that would provide athletes the same data on the run as they use (often to the exclusion of all else) on the bike. Naturally the target ranges would need to be recalibrated for running, but the underlying principles would be the same -- average X watts, don't exceed Y watts. Why don't you see that as an improvement on things like pace, HR, RPE?

Because there's nothing a runner could accomplish using a powermeter that couldn't already be accomplished using a measured distance, a watch, and some common sense.

Is this still your opinion?
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
davearm wrote:
Andrew Coggan wrote:
davearm wrote:
It's crazy to me that you think perceived exertion is the best solution to the running scenario, given what a radical departure it is from your position on cycling.


Not a radical departure in the least.

Consider, for example, the possibility of pacing by power...despite exploring the idea of calculating a theoretically-optimal strategy based on the physics and physiology of cycling long before, e.g., bestbikesplit.com, my advice to people on this matter has always been to simply use their powermeter to make sure they "don't go out too hard".

Similarly, a couple of my PPPs have always been:

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

and

"If it feels hard, then it is hard"

with the point being that along side power (pace for a runner), perceived exertion is a highly valuable tool.

The radical departure I was alluding to is that training and racing with a powermeter is quantified, precise, accurate, and backed by loads of science.

Perceived exertion is basically the opposite of all these things.

So you can imagine how odd it seems when the same expert advocates one approach for one discipline, and the complete opposite approach for the other.

I advocate that all endurance athletes calibrate their perceived exertion against a reasonable surrogate for their metabolic rate, especially when the latter is also an absolute reflection/critical determinant of their actual performance ability. So, pace for runners, but power for cyclists.

And is this still your opinion?
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
dcrainmaker wrote:
Andrew Coggan wrote:
A few thoughts...

Combining the above with the fact that runners don't generally have to be able to rapidly change pace the way cyclists do, that they aren't as influenced by environmental conditions (e.g., wind), that they tend to utilize flat surfaces (tracks) for structured training, etc., and I can't see a running power meter having a significant impact on how people actually train and perform.



Honestly, I'm surprised to see you write. Mostly because it really makes no sense.

Wind is just as painful to a runner as it is to a cyclist, run a marathon into a headwind and you'll understand. Similarly, varying terrain is just as much of a factor for runners as it is cyclists. This is especially true for longer formats (i.e. half marathon and beyond) in courses with rolling terrain or worse.

I could see trying to argue it makes it's of little benefit for situations such as windless flat surfaces. But to try and argue that runners aren't impacted by hills or wind comes across a bit...out of place?

Sorry, but I think that your assertions are incorrect. Runners are clearly not impacted by wind as much as cyclists. (And yes, I say that having run a fair bit while living on a wind-swept barrier island, as well as having to finish a 30 km race under my goal of 2 h flat by running the last 2 mi as hard as I could straight into a block headwind.) Way back in 1971, for example, Pugh tested runners in a climactic chamber and demonstrated that overcoming wind resistance accounted for only 7.5% of energy expenditure when running on the flat at 3.75 m/s and 13% at 4.47 m/s. This is in contrast to cycling, whereas as we all know, overcoming wind resistance accounts for the vast majority of energy expenditure. It therefore follows that it takes a much, MUCH stronger wind to have the same impact on a runner as it does on a cyclist.

As for hills, while the effects of gradient on energy expenditure are the same in runners and cyclists, how many runners do you know are willing to routinely venture up grades so steep that they are reduced to walking, or at best, a very slow jog? Yet, thanks to gearing cyclists regularly ride up such slopes.

Now add in the fact that, in running, true sprinters generally don't race longer distances, and distance runners rarely have to truly sprint, yet cyclists in mass start races regularly have to do both, combined with the fact that a power estimator can't account for differences in runnnig economy, which are far greater between individuals than cycling economy, and the fact that running tracks (where runners typically go when they want to perform structured training) are ubiquitous whereas velodromes are relatively rare, and, well, I just don't see the point (as I told Steve McGregor almost a decade ago when he came up w/ rTSS).

And is this also still your opinion?
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Re: DCRainmaker preview of Stryd running power meter [Trev] [ In reply to ]
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Trev wrote:
Andrew Coggan wrote:
dcrainmaker wrote:
Andrew Coggan wrote:
A few thoughts...

Combining the above with the fact that runners don't generally have to be able to rapidly change pace the way cyclists do, that they aren't as influenced by environmental conditions (e.g., wind), that they tend to utilize flat surfaces (tracks) for structured training, etc., and I can't see a running power meter having a significant impact on how people actually train and perform.


Honestly, I'm surprised to see you write. Mostly because it really makes no sense.

Wind is just as painful to a runner as it is to a cyclist, run a marathon into a headwind and you'll understand. Similarly, varying terrain is just as much of a factor for runners as it is cyclists. This is especially true for longer formats (i.e. half marathon and beyond) in courses with rolling terrain or worse.

I could see trying to argue it makes it's of little benefit for situations such as windless flat surfaces. But to try and argue that runners aren't impacted by hills or wind comes across a bit...out of place?


Sorry, but I think that your assertions are incorrect. Runners are clearly not impacted by wind as much as cyclists. (And yes, I say that having run a fair bit while living on a wind-swept barrier island, as well as having to finish a 30 km race under my goal of 2 h flat by running the last 2 mi as hard as I could straight into a block headwind.) Way back in 1971, for example, Pugh tested runners in a climactic chamber and demonstrated that overcoming wind resistance accounted for only 7.5% of energy expenditure when running on the flat at 3.75 m/s and 13% at 4.47 m/s. This is in contrast to cycling, whereas as we all know, overcoming wind resistance accounts for the vast majority of energy expenditure. It therefore follows that it takes a much, MUCH stronger wind to have the same impact on a runner as it does on a cyclist.

As for hills, while the effects of gradient on energy expenditure are the same in runners and cyclists, how many runners do you know are willing to routinely venture up grades so steep that they are reduced to walking, or at best, a very slow jog? Yet, thanks to gearing cyclists regularly ride up such slopes.

Now add in the fact that, in running, true sprinters generally don't race longer distances, and distance runners rarely have to truly sprint, yet cyclists in mass start races regularly have to do both, combined with the fact that a power estimator can't account for differences in runnnig economy, which are far greater between individuals than cycling economy, and the fact that running tracks (where runners typically go when they want to perform structured training) are ubiquitous whereas velodromes are relatively rare, and, well, I just don't see the point (as I told Steve McGregor almost a decade ago when he came up w/ rTSS).


It would be very easy for Andrew Coggan to jump on the running power meter band waggon and I'm sure if he did his ideas would be embraced just as enthusiastically by runners and running coaches as is the case in cycling.

The fact that he holds this opinion may be surprising but it does show he isn't interested in making easy money.


It would seem Andrew Coggan has changed his opinion and jumped on the running power meter band wagon.
Last edited by: Trev: Dec 23, 15 12:43
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Re: DCRainmaker preview of Stryd running power meter [The1Jacker] [ In reply to ]
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The1Jacker wrote:
mamilner26 wrote:
I am interested in this product, however I will wait to see what others have to say before purchasing.


My 2 cents as someone who has a Stryd but only used it twice - until Garmin supports power in "run mode" I don't see myself using it any more. It's really interesting to see the power numbers during a run, but being in "bike mode" definitely has its drawbacks. Additionally, the file uploads to TP as a ride and makes TSS inaccurate (unless your critical run power just so happens to exactly match your FTP) even after you change it to a run so you really have to manually enter your stats as a run, then you lose all the analytics in the expanded view (charts, etc.)

Actually, that's not the case in TrainingPeaks. You just have to set things first in your athlete settings. Hopefully this helps...












And if you have past files that you've already changed, but haven't recalculated according to the run power ftp, then just do this last image's instructions for those workouts. A little time intensive if you have a lot of files, but won't need to do it after that.

Jim Vance
http://TodaysPlan.com.au (Disclosure: I am contracted with Today's Plan)
http://www.CoachVance.com/
Twitter @jimvance
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Re: DCRainmaker preview of Stryd running power meter [JimVance] [ In reply to ]
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But even with all of that, if you already had a run in you schedule, the initial run will not be marked as completed by editing a "bike" to a run. You will end up with an uncompleted run (red box), along with an unscheduled run (grey box). Really surprised that they haven't managed to work with Garmin to allow power in the run mode.
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Re: DCRainmaker preview of Stryd running power meter [J_R] [ In reply to ]
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J_R wrote:
But even with all of that, if you already had a run in you schedule, the initial run will not be marked as completed by editing a "bike" to a run. You will end up with an uncompleted run (red box), along with an unscheduled run (grey box). Really surprised that they haven't managed to work with Garmin to allow power in the run mode.


Well, your original complaint was inaccurate TSS and a longer work around. Not hard to delete the workout that didn't get data filled, and copy the details of it into the one you uploaded. And as someone else mentioned, the workout type has now been fixed, where the workout will load as a run file from Stryd's PowerCenter into TP. So it is just a matter of fixing the past workouts.

Hope this helps.

Jim Vance
http://TodaysPlan.com.au (Disclosure: I am contracted with Today's Plan)
http://www.CoachVance.com/
Twitter @jimvance
Last edited by: JimVance: Dec 23, 15 21:08
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Re: DCRainmaker preview of Stryd running power meter [JimVance] [ In reply to ]
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That was someone else's original complaint. While the Stryd Power center may now push to TP as a run workout, Garmin Connect will not. In an age where my Garmin 920xt will auto connnect to my phone or wifi router automatically, upload workout to GC and then push to TP before I am even back inside of the house, it seems ridiculous to have to make so many manual edits. Real fix, Stryd works with Garmin to allow power in run mode. I think that it will be vital to there existence.
Last edited by: J_R: Dec 23, 15 21:18
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Re: DCRainmaker preview of Stryd running power meter [J_R] [ In reply to ]
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That's a simple fix. Will happen very soon.

Jim Vance
http://TodaysPlan.com.au (Disclosure: I am contracted with Today's Plan)
http://www.CoachVance.com/
Twitter @jimvance
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Re: DCRainmaker preview of Stryd running power meter [JimVance] [ In reply to ]
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Do you have anything to base that on, or is it just speculation?

When implementing new features, the technical impediments are often minor compared to the political ones. The question is whether Garmin want to support run power, not whether they can.

I wouldn't be surprised if we don't see native Garmin support for Run Power for a long time yet, but having said that, the launch of the new Connect IQ platform that allows writing to FIT files could solve this problem. Whether the current generation of devices (e.g. 920xt and fenix 3) support that is another matter.
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Re: DCRainmaker preview of Stryd running power meter [JimVance] [ In reply to ]
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One problem I foresee is people learning to run and sustain more power but not necessarily more speed.

Or does Stryd not measure true power but calculates estimated power from speed / exceleration / weight / gradient etc?
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Re: DCRainmaker preview of Stryd running power meter [Trev] [ In reply to ]
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Trev wrote:
One problem I foresee is people learning to run and sustain more power but not necessarily more speed.

Or does Stryd not measure true power but calculates estimated power from speed / exceleration / weight / gradient etc?

Is that similar to biking with more power but not more speed?
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Re: DCRainmaker preview of Stryd running power meter [Mike Prevost] [ In reply to ]
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Mike Prevost wrote:


Exactly my point. On a bike, power to go a specific speed varies with wind direction. Same with this system. This is exactly what you want. It IGNORES wind, just like a bike power meter and measures only the power you are producing. It does not have to account for wind and should not. On a bike, you have speed and power. On this device you have pace and power. That is all you need. In other words, this system is estimating power by measuring acceleration. The estimate of power is dependent of wind, as it should be.


Absolutely and provably not true.

On a bike, the power you expend is:

P = CdA * 0.5 * rho * w^2 * v + m*( a + Crr*g)*v + m*g*s*v ,
where
w is airspeed
v is ground speed
s is slope

How does measuring only "a", "v", and "s" give you the total power, P? What kind of sorcery is this? :-)

Quote:

Using your example, run a 6:00 pace into a head wind VS tail wind and you will have to produce a higher acceleration into the wind, which presumably this device will measure, therefore more watts. Just like a bike pwoermeter. Wind does not matter for measurement purposes.


No, that's not the way physics works.

Newton's Second Law of Motion states that:
m*a = sum of forces on a body

So acceleration is 1/m times the net sum of forces on a body. Acceleration is the result of net power application. Not the cause of it.

AndyF
http://alphamantis.com
#findyouraero
Last edited by: AndyF: Dec 24, 15 6:30
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Re: DCRainmaker preview of Stryd running power meter [AndyF] [ In reply to ]
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AndyF wrote:
Acceleration is the result of net power application. Not the cause of it.

Weight gain is the result of excess caloric intake, not the cause of it. Yet, by measuring the former I can calculate the latter, at least provided other factors are constant. :)
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Re: DCRainmaker preview of Stryd running power meter [J_R] [ In reply to ]
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J_R wrote:
Real fix, Stryd works with Garmin to allow power in run mode.

Or with some other major manufacturer, anyway.
Last edited by: Andrew Coggan: Dec 24, 15 7:08
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Re: DCRainmaker preview of Stryd running power meter [Jctriguy] [ In reply to ]
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On a bike speed is also dependent on aerodynamics.

Running only marginally so if at all.

It's possible to run in such a manner as to produce considerable power but generate little speed if you run inefficiently or with ineffective style.

So cycling if you increase power you will increase speed but running an increase in power does not necessarily increase speed.

Style or technique makes little or no difference to power output when cycling, but running is a very different kettle of fish.
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
AndyF wrote:
Acceleration is the result of net power application. Not the cause of it.


Weight gain is the result of excess caloric intake, not the cause of it. Yet, by measuring the former I can calculate the latter, at least provided other factors are constant. :)

I was just using this as a teaching opportunity, re-stating a law of motion that carefully differentiates between applied forces and state variables. The distinction between state parameters -- variables that intrinsically describe the object's state (like x, v, CdA, and Crr) -- and forces is an important one in mechanics.

I'll leave you with this provocative (and completely tangential) quote from one of the masters of mechanics, V.I. Arnold ( in Mathematical Methods of Classical Mechanics ):

Quote:
The initial state of a mechanical system ( the totality of positions and velocities of its points at some moment of time) uniquely determines all of its motion.

It is hard to doubt this fact, since we learn it very early. One can imagine a world in which to determine the future of a system one must also know the acceleration at the initial moment, but experience shows us that our world is not like this.
Just to be clear: I'm not arguing your point, Andy. I just wanted to add the notion of Newton's law of determinacy. Teaching moment, once again.

AndyF
http://alphamantis.com
#findyouraero
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Re: DCRainmaker preview of Stryd running power meter [AndyF] [ In reply to ]
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AndyF wrote:
I'm not arguing your point, Andy.

No, you were arguing rroof's.
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Re: DCRainmaker preview of Stryd running power meter [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
AndyF wrote:
I'm not arguing your point, Andy.


No, you were arguing rroof's.

I just meant that I wasn't challenging what you had said.

AndyF
http://alphamantis.com
#findyouraero
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Re: DCRainmaker preview of Stryd running power meter [ In reply to ]
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Stryd thought experiment:

1) Picture a person wearing a spacesuit standing on a tiny planet. The planet is so tiny that not only is the gravitational field too weak to hold an atmosphere (hence the need for the spacesuit), but also so weak that the individual can achieve orbital velocity by pushing off in a single step. They do so, and now orbit the planet forever without ever touching down again. What is their "running" speed over the surface of the planet? What is their power output?

2) Picture the exact same person wearing exactly the same spacesuit standing on Earth, while wearing the Hoverbelt^tm they got for Christmas. The Hoverbelt^tm reduces their weight to exactly the same value as in scenario #1 above. They push off exactly as before as well. Do they achieve orbital velocity, or do they eventually settle back down to Earth and have to push off again? if the latter, how does their power output differ/compare to scenario #1?
Last edited by: Andrew Coggan: Dec 26, 15 5:48
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