# Help from Power Gurus



## pagey (Oct 30, 2009)

I need some help deciphering the following power numbers. I'm newish to power having had a PM since Sept last year, and am struggling to determine my FTP.



Last August I conducted a VO2max lab test, with the following results



VO2Max Peak - 57.3 @ 325W @ 186bpm

Threshold - 250W @ 158bpm

Weight - 68kg



On Sat I conducted a 20min FTP Test on my turbo trainer with the following results

Avg W = 210w @ 166bpm (so FTP @ 95% = 200w) I thought was really pushing hard in this test.

On Sun I conducted a 2hr ride that included 2 x 20min sustained climbs (Mt Dandenong if anyone knows it)

1st climb after 20min warm up - 5km avg grade 6.6% 20min

Avg W = 280w @ 170bmp

2nd climb after 10min downhill recovery - 5.4km avg grade 5.8% 20min

Avg W = 232 @ 164bpm

Not sure what to make of these numbers. Any insight would be grateful.


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## Clyde250 (Feb 24, 2007)

My wattage always goes up while riding outside. Not sure why but it is around 30W higher. It may have something to do with the mental distraction of steering and scenery.


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## Wookiebiker (Sep 5, 2005)

Technically you should register the same power numbers inside as you do outside since power is power.

However, generally speaking most people seem to register 15%-30% lower power numbers inside. I think the general consensus is the small flywheel on trainers makes it harder to keep the power as high.

The reality is you are getting as good of a workout as outside, especially since you get no breaks on a trainer (i.e. you are pedaling the whole time, no coasting).


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## ZoSoSwiM (Mar 7, 2008)

My wattage goes up slightly outdoors but not a ton. It is a lot more variable though. The largest differences are in my peak short duration power outputs. There is no way I can reach 1200watts inside but I can outdoors. 

Besides motivation, enjoyment, and move freedom of movement one of the largest influences on power between outdoors and indoors is cooling. Sure you have a big fan blowing on you indoors but don't think for a second it's as effective as the wind is outside.


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## iliveonnitro (Feb 19, 2006)

"Threshold" on VO2max tests is lower than FTP. From your demonstrated performance, I would venture a guess around 260w. The 210w test was probably an anomaly.


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## Alex_Simmons/RST (Jan 12, 2008)

We don't know which result is an anomaly as OP was using a Power 2 Max and is likely experiencing torque zero drift.


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## Rhino4Five (Nov 5, 2009)

Well, in the very worst case (assuming you were calibrated), your FTP is not lower than 266 watts (280 watts x 95%).

Did you have adequate cooling when you were riding indoors? My numbers drop if I start to overheat.


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## Alex_Simmons/RST (Jan 12, 2008)

Rhino4Five said:


> Well, in the very worst case (assuming you were calibrated), your FTP is not lower than 266 watts (280 watts x 95%).
> 
> Did you have adequate cooling when you were riding indoors? My numbers drop if I start to overheat.


Given that the data quoted is most likely highly suspect, I would suggest it's probably no where near that high.


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