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Has skills-will travel
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Discussion Starter · #1 ·
I am wondering if anyone has any information on how Elevation affects FTP?

The reason for the question is, I live at 8500 ft and have been doing all my winter training at this elevation. I have also been doing my FTP test every 4 to 6 weeks. Yet, during the warmer months – I train at ~6000 ft, which is also where I do my FTP tests during that time. I am trying to compare my power today to what it was during the summer and fall, yet I think doing my tests at higher elevation are yielding a lower FTP than if I was doing them 2500 ft lower?

Thanks!
 

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Yes, FTP is affected by elevation. By how much? I don't think a formal study has ever been done.

I remember GlenzX (racer who used to post here a lot) moving from Sante Fe to the east coast, and saying how much more power he can put out at sea level.

Also, one of our local phenoms blogged that he put out his 400W 20min PR at sea level as well. It does make a difference. He travels a lot for racing, so he has lots of data.

I'm remember 10W FTP for every 5000 feet, or something like that, just from others stating their experience. Your best bet is to always test at the same elevation. To get your best numbers, I would go down to the valley.
 

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A guy on the google wattage group posted this a few months ago.

I came across this blog
posting which purports to merge a few studies into one table:http://www.twowheelblogs.com/how-altitude-affects-power-output

for what it's worth, it implies that if one rides at sea level then
ascends to 6,000', their FTP will be 92% of that at sea level. If one
rides at 6,000' then goes to sea level, their FTP will be 108.7%
(=1/0.92) of their FTP @ 6,000'.

in brief:
Altitude
Feet Meters % FTP
0 0 100%
1000 300 99%
2000 610 98%
3000 910 96%
4000 1220 95%
5000 1520 93%
6000 1830 92%
7000 2130 90%
8000 2440 88%
9000 2740 86%
10,000 3050 83%
11,000 3350 81%
12,000 3660 78%
13,000 3960 75%
14,000 4270 72%

Again the table posted is a metanalysis, and as such, can be
considered a pretty good *ballpark*, for a *population*. The culled
studies generally where investigating *acute responses* at altitude in
unacclimated sea level subjects. So:
1) It has been demonstrated that individual responses to altitude are
variable. Your response may vary considerably from what the table
ballparks.
2) The culled studies used for the metanalysis were not investigating
acute response to sea level after living (or acclimating) at
altitude. Using the data to derive a reverse (altitude to sea level)
prediction has validity issues. Studies have been inconclusive in
this regard, and again, the responses may vary individually.
3) The blog author's use of the table to derive an expected response
in one who is acclimated at 3000ft then performing at 10000ft has
validity issues because the author a) assumes that the table is valid
in calculating the reverse response (going from 3000' to sea level),
and b) assumes that a 3000' acclimated individual will have a response
that follows the same linearity* to 10000' as an unacclimated
population. *and whether individuals (as opposed to population
metrics) display a *linear* response to increasing altitude exposure
is also a matter of debate
 

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Has skills-will travel
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372 Posts
Discussion Starter · #4 ·
Ponch - I haven't been able to bike at lower elevations to see the difference yet, this weekend I will go to St George to Road Bike with the little lady, so I will be able to see what difference there is, yet won't be able to do a full FTP test as my little lady would be pissed at me for dropping her. One day, you and I will need to meet as we race the same age class and Cat, so I am sure I have raced against you in the past - just don't know who you are?

Chiva - exactly what I was looking for, so it seems that I would have roughly a 5% decrease in Power at 8500 ft vs 6000 ft. Thanks! Now I can compare my summer tests to my winter test.
 

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AK kid who LOVES bikes!
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What I’ve heard is that ftp decreases 1-2 percent per 1,000’ of elevation depending on who you are. Some people perform better at higher altitudes than others. That’s why some people at the top of pikes peak in Colorado are short of breath after walking while others will literally pass out just sitting in the parking lot. It’s all about how efficient your lungs are at gathering oxygen AND using it. So there is no exact formula for everyone because some are better at elevation than others. It’s purely a genetic thing.
 

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for what it's worth, it implies that if one rides at sea level then
ascends to 6,000', their FTP will be 92% of that at sea level. If one
rides at 6,000' then goes to sea level, their FTP will be 108.7%
(=1/0.92) of their FTP @ 6,000'.

in brief:
Altitude
Feet Meters % FTP
0 0 100%
1000 300 99%
2000 610 98%
3000 910 96%
4000 1220 95%
5000 1520 93%
6000 1830 92%
7000 2130 90%
8000 2440 88%
9000 2740 86%
10,000 3050 83%
11,000 3350 81%
12,000 3660 78%
13,000 3960 75%
14,000 4270 72%
If I ascended 14k in one climb, I'd be at a lot lower ftp % than just 72% of my max LOL.

(kidding, obviously.....i know what you guys are implying)
 
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