FTP W/kg - which weight are we talking about?

[Patchelicious]

Read this.... Its from the horses mouth

 

https://www.trainingpeaks.com/blog/what-is-threshold-power/

[koukie]

Your 20 minute effort is NOT your FTP. Its a measurement that can be used for training, but its NOT your FTP:

 

"Functional Threshold Power (FTP) represents your ability to sustain the highest possible power output over 45 to 60 minutes, depending on whether you're a trained athlete or not. As a result 95% of the 20 minute average power is used to determine FTP."

 

​So by all means use it, but don't quote it as your FTP.

Are you also saying that the 95% of 20 min is not your FTP? I reckon madmarc was referring to his 95% of 20min?

[Patchelicious]

Are you also saying that the 95% of 20 min is not your FTP?

No I am not. 95% of your 20minute effort is a very good indicator of your FTP and you can use that as your FTP, as is 90% of your 8min efforts. Like I said, use any numbers you want for training, as long as you use them consistently. Training is not only about FTP. 1min 2 min 3 min 5 in, 10 min 20 min 40min efforts are all important, hence power graphs.

 

I am however saying. Don't quote your 20minute effort as your FTP. Functional Threshold Power is a defined metric. It is seen as your best 60minute effort. There are ways of calculating this effort, and the 95%/90% ones are just ways of arriving at this metric.

[madmarc]

Your 20 minute effort is NOT your FTP. Its a measurement that can be used for training, but its NOT your FTP:

 

"Functional Threshold Power (FTP) represents your ability to sustain the highest possible power output over 45 to 60 minutes, depending on whether you're a trained athlete or not. As a result 95% of the 20 minute average power is used to determine FTP."

 

​So by all means use it, but don't quote it as your FTP.

Maybe i'm misunderstood in my last sentence  - the above statement from Wattbike is exactly how I do my FTP test - In fact I've tried a longer test of 40 min and the results were within 1 or 2 w/kg of each other.

[Patchelicious]

Maybe i'm misunderstood in my last sentence  - the above statement from Wattbike is exactly how I do my FTP test - In fact I've tried a longer test of 40 min and the results were within 1 or 2 w/kg of each other.

I think you are misunderstanding me.

 

HOW you arrive at your FTP is one thing. There are many cool ways of doing this, and lots of coaches will have different ways and test, most of them very accurate.

 

WHAT your FTP is another.

 

This is either your tested 60min effort or your estimated 60min effort (done with tests like mentioned) 

 

Mach 1 is Mach 1 

[Frosty]

The obsession of W/Kg - I'm sure some people don't even understand how to use it properly. It's more than just FTP/Mass, but rather Peak Power Output divided by Mass.

 

edit: peak power is measured over different duration, i.e. 5s, 30s, 1m, 5m, 20m and 1h. A sprinter usually has a lower 20m an 60m PPO compared to a Time Trialist or Pursuiter.

 

Read this for some further insight: https://www.trainingpeaks.com/blog/power-profiling/

 

 

And now to answer the OP's question... I use my birthday suit weight (variable) + kit (shoes, shorts, shirt and socks - constant).

[Fat Boab]

Maybe i'm misunderstood in my last sentence  - the above statement from Wattbike is exactly how I do my FTP test - In fact I've tried a longer test of 40 min and the results were within 1 or 2 w/kg of each other.

 

Wouldn't 1 to 2 W/kg variance be quite significant?

[lechatnoir]

Wouldn't 1 to 2 W/kg variance be quite significant?

 

Reading at Patch says, and knowing what I know, 1-2 W/kg is 80-160W for an 80kg rider... Flip!! I could do with an extra EIGHT, nevermind 80!!! 

[koukie]

Wouldn't 1 to 2 W/kg variance be quite significant?

Yes that is huge.

[Fat Boab]

As I know sweet FA about power training, I'm hardly qualified to dish out words of wisdom on the topic, but maybe 30-odd years of being an engineer can bring some insights to the topic of normalisation. Normalisation allows you to compare one parameter, with another, hopefully independent, parameter, to gain a more informed insight into a complex situation. One often normalises data to better track changes, bench-mark against standards, or in some cases to predict associated behaviour.

As others have mentioned, if you're trying to track changes, hopefully improvements, of training on FTP W/kg, then presumably the 'engine's' mass on the day of the test would be relevant eg buck-naked mass.

 

If you're trying to compare yourself against others or standards (have a google for category racers and 'typical' ranges of W/kg, as an example), then make sure you use the same definition of mass, as well as power. No doubt differing authors, systems, or thick thumbs on their calculator, can make differing assumptions (quite common without peer review to try and ensure standards are applied).

 

If you're interested in using W/kg to try and predict/estimate, for instance VAM, as happens every TdF by various commentators to try and suggest the influence of doping, then again make sure of the mass definition. In this example, it would probably be best to use the total mass of rider, bike, bottles etc, which are ascending, which is quite variable in itself. I've played with this approach to track the impact of training on VAM on the same hill, across time, under differing weather conditions etc, by inferring my power output, using some basic mechanics (I don't have a power meter). It's certainly only an approximation, but I make sure to use my mass on the day plus the extra mass of bike, clothes etc etc.  

 

Horses for courses......

[Fat Boab]

Reading at Patch says, and knowing what I know, 1-2 W/kg is 80-160W for an 80kg rider... Flip!! I could do with an extra EIGHT, nevermind 80!!! 

 

I'm interested - so an improvement of 8 W on 80 kg ie a 0.1 W/kg increase, is aspirational? 

[Eon du Plessis]

I'm interested - so an improvement of 8 W on 80 kg ie a 0.1 W/kg increase, is aspirational?

That would depend. If yiu are already close to your maximum potential, it can be a lot. If you've only just started training, it's probably not so impressive.

My wife went up 30W in a month of training using power. That's from having virtually zero cycling fitness.

After that first month, things have calmed down a lot and she would probably be happy with 5W gain per month.

 

 

Sent from my iPhone using Tapatalk

[koukie]

.

 

['Dale]

The trouble with the FTP is that it drops when training diminishes.

 

Pity.

[Frosty]

Yes I would think a 10% is quite significant.

Careful... 8W for an 80Kg rider is not a 10% gain on W/Kg  

8W / 80Kg = 0.1 W/Kg, but compared to, say 3W/Kg is 3.3%, or at 6W/Kg = 1.66%

 

However, a 10% gain is significant.

[koukie]

Careful... 8W for an 80Kg rider is not a 10% gain on W/Kg  

8W / 80Kg = 0.1 W/Kg, but compared to, say 3W/Kg is 3.3%, or at 6W/Kg = 1.66%

 

However, a 10% gain is significant.

Correct I realized my mistake that is why my post was deleted.