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Can someone explain Garmin FTP new records to me?

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Can someone explain Garmin FTP new records to me?

Old 08-26-21, 08:43 AM
  #26  
chaadster
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Originally Posted by NoWhammies
So. My Garmin has the 'auto FTP calculations' feature enabled. Back in June I sent out and did a very hard/fast ride. At the end of the ride, my Garmin said "Congratulations! You set a new FTP record. Do you accept?". And yes, this was in fact a new FTP record for me because I knew what my old FTP was. So I clicked yes.

A few weeks later I was out for a ride. A fast ride, but nothing like the ride back in June. At the end of the ride my Garmin said "Congratulations! You set a new FTP record. Do you accept?" Now, this FTP was definitely slower than the one from June. So I clicked no. I then went in an doubled checked my Garmin FTP setting. It was the higher setting from June.

A month or so after that I was out on a fast ride and again. At the end of the ride my Garmin said "Congratulations! You set a new FTP record. Do you accept?" This FTP was again lower than the June FTP. But what the heck, I said yes and went on with my day.

This has happened a few times since. Sometimes the FTP is higher than what is recorded, other times lower.

Anyone have any idea what's going on here? The only thing I can come up with is the FTP calculation involves weight, correct? And I use my Garmin scale daily. So is Garmin calculating a new FTP for me each time based on my weight? Thank you.
I don’t use and cannot speak to the Garmin software, but I have been doing power-based training with a cycling coach for 11 years and have some thoughts which may be helpful to you.

First, I would not be concerned with the Garmin FTP estimates every few weeks. If you were on a training regimen, you’d need to give the training time to work so a new estimate based on non-specific activities every few weeks doesn’t matter, and if you’re not on a training regimen, what does a bi-weekly FTP estimate matter? You’ve already indicated that you’re aware of perceived exertion and so it doesn’t sound like you’re metering your efforts based on FTP either.

FTP outside of a training plan just doesn’t mean much, and if it’s estimated based on efforts which are not specifically performed to evaluate maximum power output (for an hour, i.e FTP) then it means even less.

I’d suppose it’s nice that Garmin asks if you want to accept new estimates because the machine cannot otherwise know if you made a specific maximum effort to evaluate FTP. I would not accept a new estimate unless I had.

I also would not concern myself with a new FTP estimate unless I was consistently riding well beyond my numbers to the point the zones were irrelevant or I was doing a structured training regimen which I wanted to evaluate the results of.

None of that is to say there’s only one right way to ise FTP, but the number can be misused, assumed to mean things it does not. For example, a lower FTP estimate from Garmin than what it estimated two weeks prior does not mean you should change your behavior…especially if you did not specifically perform an effort to evaluate FTP and/or you’re not on a training program to increase FTP.

Yes, Garmin is offering tools to make training easier, and I’ve no doubt they are helpful when used properly in the course of training. I’m not aware of any training program which requires FTP assessment every couple-or-three weeks, nor every fast/hard ride. Garmin provide the service, but it’s incumbent on the rider to use it properly.

In short, ignore the FTP estimates except in cases where you’re riding to evaluate FTP.
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Old 08-26-21, 09:48 AM
  #27  
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Originally Posted by asgelle
Or your VO2max remained the same/decreased accompanied by an increase in anaerobic work capacity, or lactate tolerance, or threshold power as a fraction of VO2max, ...
W' decreased. 5 minute power does not increase 40+ watts without concomitant increase in VO2 max, VO2 max would not decline 15% at the same time.

If you read Firstbeats white papers and the patent and if you believe the numbers I wrote, the only conclusion is they estimate the VO2 max based on speed and HR with perhaps a trivial nod to power but it is impossible to know.

Just answer this. Do you think there is a single 63 year old human with a VO2 max at 73?

If not, what is the simplest explanation? Here it is.....The Garmin sees an average speed of 27-28 mph for 10-15 miles and a HR of 130 BPM, it comes up with a high VO2 max based on those two values. I know the exact ride that it assigned me that high VO2 max, my power was only in the 200-220 watt range, so, it is impossible for the Garmin to have used it in the calculation.
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Old 08-26-21, 11:13 AM
  #28  
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Table 1 of FirstBeat's white paper lists the METs and VO2 in ml/kg/min for 20 and 30 km/hr

7.1 METs 25 mk/kg.min (20 km/hr)

9.8 METS 34 ml/kg (30 km.hr)

There is no mention of power nor any apparent understanding of aerodynamic forces. Speed increases 50% but workload only increases 38%. Laughable. The actual power increase from 20 to 30 km/hr on a standard road bike is nearly tripled.

https://assets.firstbeat.com/firstbe..._30.6.2017.pdf
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Old 08-26-21, 03:51 PM
  #29  
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Originally Posted by GhostRider62
Here are some facts, I went from a recumbent with a CdA of around 0.160 m^2 to an upright with CdA of around 0.360 m^2 during which time my VO2 max power increased 46 watts. Logic would say my VO2 max increased during that time. Yet, my Garmin reported a decrease from 73 to 61 ml/kg.
Wait, let me get this straight...

You know your drag coefficient down to three decimal places, for two different bikes. And you're using Garmin's consumer-level equipment and software to estimate VO2.

Then you say their algorithm is garbage. Probably right. (I wouldn't say garbage, but certainly not highly precise and reliable.)

You seem like someone who should go to a sports physiology lab and pay to have your VO2 measured accurately (FTP as well, and any other metrics they can provide).

The Garmin app is just for those of us who like to game-ify our workouts. Are you an engineer? You will be able to find faults anytime you go looking for them. You should expect to see some flaws in this data. But here's the thing: you didn't pay thousands of dollars for precisely calibrated equipment, used in a controlled environment and operated by trained professionals.
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Old 08-26-21, 05:09 PM
  #30  
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Originally Posted by Broctoon
Wait, let me get this straight...

You know your drag coefficient down to three decimal places, for two different bikes. And you're using Garmin's consumer-level equipment and software to estimate VO2.

Then you say their algorithm is garbage. Probably right. (I wouldn't say garbage, but certainly not highly precise and reliable.)

You seem like someone who should go to a sports physiology lab and pay to have your VO2 measured accurately (FTP as well, and any other metrics they can provide).

The Garmin app is just for those of us who like to game-ify our workouts. Are you an engineer? You will be able to find faults anytime you go looking for them. You should expect to see some flaws in this data. But here's the thing: you didn't pay thousands of dollars for precisely calibrated equipment, used in a controlled environment and operated by trained professionals.
CdA measurement is free. VO2 max and CdA should not be related, they are in this instance because Garmin (FirstBeatoff) are lazy. They assume power and speed are linear. But, they cannot even get that right, a 50% increase in speed should correspond to a 50% increase in power NOT 38% as their white paper indicates. If they want to use a faulty model, at least use it correctly,

Carts cost a lot. Do you think someone my age could possibly have the VO2 max indicated by Garmin? Y

Yes, I am an engineer.

Garmin should focus on their wheelhouse. Navigation. Like get a good GPS antenna.

Their VO2 max and overall training advice sucks. Anyone with any STEM background beyond 8th grade and who reads the paper should take caution

Edit: I have paid. I know my VO2 max. So, I am not guessing here.
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Old 08-26-21, 05:16 PM
  #31  
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Originally Posted by GhostRider62
... a 50% increase in speed should correspond to a 50% increase in power ...
A 50% increase in speed can never result from a 50% increase in power. This might help https://www.recumbents.com/wisil/Mart...%20cycling.pdf
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Old 08-26-21, 05:29 PM
  #32  
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Originally Posted by asgelle
A 50% increase in speed can never result from a 50% increase in power. This might help https://www.recumbents.com/wisil/Mart...%20cycling.pdf
I suspect you did not read my posts carefully. Do you think someone who can ascertain the CdA of their recumbent vs upright doesn't understand the basic physics. The link is a 404

Garmin and firstbeat is assuming a linear relationship.

I really do not need help.

Last edited by unterhausen; 08-26-21 at 06:45 PM.
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Old 08-26-21, 07:30 PM
  #33  
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Well said chaadster Thank you.
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Old 08-26-21, 08:32 PM
  #34  
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Originally Posted by GhostRider62
Garmin should focus on their wheelhouse. Navigation. Like get a good GPS antenna.
Well, there’s something we agree on.
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Old 08-27-21, 05:47 AM
  #35  
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I"m not sure how this turned into a contentious subject. If a garmin engineer said they knew how to find their car in the parking lot, I would ask for proof.

There are probably some more useful metrics that they could derive if the rider has a power meter and heart rate monitor, but they aren't as well known as VO2. You can run apps on most newer garmin devices, I imagine someone has one that will display better metrics.
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Old 09-29-21, 05:26 AM
  #36  
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Originally Posted by GhostRider62
They assume power and speed are linear. But, they cannot even get that right, a 50% increase in speed should correspond to a 50% increase in power NOT 38% as their white paper indicates. If they want to use a faulty model, at least use it correctly,
If they have a linear component AND a static component (e.g. rolling resistance) then the model for aerodynamic drag can be linear while the total power increase needed would not be linear.

I'm not saying they do - I can't really find the model they use to begin with, just giving an alternate explanation to what you consider incorrect (50% vs 38% power with a 50% speed increase).
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Old 01-29-22, 06:05 PM
  #37  
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Originally Posted by chaadster
I don’t use and cannot speak to the Garmin software, but I have been doing power-based training with a cycling coach for 11 years and have some thoughts which may be helpful to you.

First, I would not be concerned with the Garmin FTP estimates every few weeks. If you were on a training regimen, you’d need to give the training time to work so a new estimate based on non-specific activities every few weeks doesn’t matter, and if you’re not on a training regimen, what does a bi-weekly FTP estimate matter? You’ve already indicated that you’re aware of perceived exertion and so it doesn’t sound like you’re metering your efforts based on FTP either.

FTP outside of a training plan just doesn’t mean much, and if it’s estimated based on efforts which are not specifically performed to evaluate maximum power output (for an hour, i.e FTP) then it means even less.

I’d suppose it’s nice that Garmin asks if you want to accept new estimates because the machine cannot otherwise know if you made a specific maximum effort to evaluate FTP. I would not accept a new estimate unless I had.

I also would not concern myself with a new FTP estimate unless I was consistently riding well beyond my numbers to the point the zones were irrelevant or I was doing a structured training regimen which I wanted to evaluate the results of.

None of that is to say there’s only one right way to ise FTP, but the number can be misused, assumed to mean things it does not. For example, a lower FTP estimate from Garmin than what it estimated two weeks prior does not mean you should change your behavior…especially if you did not specifically perform an effort to evaluate FTP and/or you’re not on a training program to increase FTP.

Yes, Garmin is offering tools to make training easier, and I’ve no doubt they are helpful when used properly in the course of training. I’m not aware of any training program which requires FTP assessment every couple-or-three weeks, nor every fast/hard ride. Garmin provide the service, but it’s incumbent on the rider to use it properly.

In short, ignore the FTP estimates except in cases where you’re riding to evaluate FTP.
hey I did the Garmin FTP test today in which it had me increase the power intensity every 4 minutes and got to the point where I was over exhausting myself because the power numbers it wanted me to produce were too high for me. So the last two, 4 minute intervals I did not produce those numbers in their entirety of the duration. Do you think that affected my FTP number because I did not produce the numbers requested by Garmin in the FTP test? In other words, if I were to do the FTP test on my own and push my hardest for twenty minutes, my power numbers would be lower then what Garmin asked me to produce. Also should I have the auto calculate on or off if I'm performing the FTP test using the edge device? Thank you
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Old 01-29-22, 06:55 PM
  #38  
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What is probably more useful is mapping your entire power duration(PD) curve from 5 seconds to 40-60 minutes. I don't trust Garmin for these types of tasks.

If the PD curve tells you you can ride 10 minutes at say 300 watts and you have a 10 minute climb, you know not to try it at 330 watts.

GoldenCheetah, TrainingPeaks, XERT, ZWIFTPower, and others will do this mapping/modeling for you. GC is free.

FTP estimates based upon 20 minute power is a bit of a crapshoot. FTP might represent 92% of the 20 minute power for some and 96% for others. This 4% difference could matter a lot within the context of a time crunched training plan that does a lot of intensity. In short, it could mean the difference between being able to do the program and the program doin you.
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Old 01-29-22, 07:30 PM
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Originally Posted by GhostRider62
What is probably more useful is mapping your entire power duration(PD) curve from 5 seconds to 40-60 minutes. I don't trust Garmin for these types of tasks.

If the PD curve tells you you can ride 10 minutes at say 300 watts and you have a 10 minute climb, you know not to try it at 330 watts.

GoldenCheetah, TrainingPeaks, XERT, ZWIFTPower, and others will do this mapping/modeling for you. GC is free.

FTP estimates based upon 20 minute power is a bit of a crapshoot. FTP might represent 92% of the 20 minute power for some and 96% for others. This 4% difference could matter a lot within the context of a time crunched training plan that does a lot of intensity. In short, it could mean the difference between being able to do the program and the program doin you.
thank you. Is looking at my power graph on Garmin the same thing? I'll try golden cheetah. I'm assuming zwift power is their paid version right?
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Old 01-29-22, 07:55 PM
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Originally Posted by Feelgood1
hey I did the Garmin FTP test today in which it had me increase the power intensity every 4 minutes and got to the point where I was over exhausting myself because the power numbers it wanted me to produce were too high for me. So the last two, 4 minute intervals I did not produce those numbers in their entirety of the duration. Do you think that affected my FTP number because I did not produce the numbers requested by Garmin in the FTP test? In other words, if I were to do the FTP test on my own and push my hardest for twenty minutes, my power numbers would be lower then what Garmin asked me to produce. Also should I have the auto calculate on or off if I'm performing the FTP test using the edge device? Thank you
Sorry, but I’m not familiar with the Garmin FTP test, or how it’s used within the Garmin training system, so I cannot answer any of your questions.

Taking a wild, flying guess with regards to the FTP test affecting your FTP number, yes, I imagine it does. That said, FTP tests are usually all-out (or maximal) efforts for the given duration, so getting to the point where you could not sustain the asked-for power numbers was probably appropriate— it sounds like a “ramp test”— and not specific to you, in the sense the Garmin did not expect you should have been able to do it. In other words, the point of a ramp test is to test to exhaustion.

Hopefully someone with specific knowledge will chime in for you. Again, sorry I couldn’t help.
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Old 01-29-22, 10:11 PM
  #41  
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Originally Posted by Feelgood1
thank you. Is looking at my power graph on Garmin the same thing? I'll try golden cheetah. I'm assuming zwift power is their paid version right?
I can't say because I have not faith in the Garmin software. My 1030 will tell me my training is unproductive or tell me you suck, "-6" or some rubbish when in fact I know my training was going very well. Since I have no insight into their methodology and since I know it does not correlate to my performance, I simply ignore it. In the Fall it was telling my me VO2 max was 73 or 74 which was utter BS.

One thing to recognise. The power duration curve is not one ride. It is a composite curve of all your best efforts. So, your best 5 second effort might be a hill sprint one day and a week later your best 5 minute power could be a hill climb that you went really hard on.

This is a Power Duration curve. The thick green line with dots represents actual performance. The thin green line is the curve fit to represent modeled performance. The red line was that particular race. If you see at say 2 minute, the rider could do 400 watts. This gives you some indication of realistic performance. If you sign up for some training and it says do 2 minute intervals at 430 watts, you know it is stuffed. Garmin has a forum, I would ask there. To be honest, I have never heard of someone using Garmin for training.

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