# FTP up, speed the same?



## kilgoretrout (Dec 16, 2013)

I did an FTP test today and increased my watts by 20 over an FTP test done 8 weeks ago. However, the average speeds for both tests were the same. How is that possible? If I put in more power over the 20 minutes then shouldn't the speed be up as well?

Both were the same 20 minutes tests, same bike, same trainer, same tire pressure, same flywheel/tire tension, same temp.


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## nsfbr (May 23, 2014)

Was the speed and power constant? If not, you could easily change one without the other as the loading is not going to be linear. To illustrate, say you spent 30 minutes going 20 mph and 30 minutes going 10 mph in one 60 minute test - you will have gone 15 miles, or an average of 15 mph. Compare that with just going 15 mph for 60 minutes and I assure you that the former will consume more energy, and hence average a higher power, than the latter. 

I don't know if something like that happened, but that would be one explanation from the physics side of things.

Not that I know what an FTP is, other than a way to move files between computers.


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## Alex_Simmons/RST (Jan 12, 2008)

kilgoretrout said:


> I did an FTP test today and increased my watts by 20 over an FTP test done 8 weeks ago. However, the average speeds for both tests were the same. How is that possible? If I put in more power over the 20 minutes then shouldn't the speed be up as well?
> 
> Both were the same 20 minutes tests, same bike, same trainer, same tire pressure, same flywheel/tire tension, same temp.


Speed is a function of the energy supply (power you put into the crank) and the energy demand (resistance forces). 

If power has really gone up but speed remained the same, then the resistance forces must have been higher. Not all trainers provide consistent resistance from session to session, or during a session. There are various reasons for that.

Alternatively, your power measurement may be incorrect. That could depend on a number of things as well, so for starters it would help to know how you are measuring and recording power.

It could be a combination of both.


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