Strava FTP estimate
#1
Senior Member
Thread Starter
Strava FTP estimate
Curious how accurate you feel the Strava FTP estimate is based on your experience. It's fairly accurate for me, but curious what others feel.
#4
just another gosling
Join Date: Feb 2007
Location: Everett, WA
Posts: 19,534
Bikes: CoMo Speedster 2003, Trek 5200, CAAD 9, Fred 2004
Mentioned: 115 Post(s)
Tagged: 0 Thread(s)
Quoted: 3889 Post(s)
Liked 1,938 Times
in
1,383 Posts
Interesting that it's most accurate on long climbs.
__________________
Results matter
Results matter
#7
Version 7.0
Join Date: Oct 2006
Location: SoCal
Posts: 13,127
Bikes: Too Many
Mentioned: 297 Post(s)
Tagged: 0 Thread(s)
Quoted: 1340 Post(s)
Liked 2,482 Times
in
1,457 Posts
Likes For Hermes:
#8
Non omnino gravis
Now the Strava "estimated power" over a typical ride under normal conditions? Might as well be a random number generator.
#9
Senior Member
Join Date: Mar 2010
Location: Seattle, WA
Posts: 23,208
Mentioned: 89 Post(s)
Tagged: 0 Thread(s)
Quoted: 18883 Post(s)
Liked 10,646 Times
in
6,054 Posts
More accurate than rolling dice. Less accurate than an educated guess.
#10
Me duelen las nalgas
Join Date: Aug 2015
Location: Texas
Posts: 13,513
Bikes: Centurion Ironman, Trek 5900, Univega Via Carisma, Globe Carmel
Mentioned: 199 Post(s)
Tagged: 0 Thread(s)
Quoted: 4560 Post(s)
Liked 2,802 Times
in
1,800 Posts
It's most accurate on loops, circuit rides, which negate differences due to wind and elevation.
Same as the various online calculators for power/etc. These work best when wind is factored into one-direction segments and routes. Lends a dose of reality to my handful of top tens on Strava. Factor in the tailwind and my 300+ watts over 15-20 minutes turns out to be closer to 100 watts.
I've compared my Strava and online calculator power guesstimates against other folks my size who do use power meters on the same routes in the same or similar conditions. Close enough for my purposes. If it's off by 5-20 watts, no big deal. Until I can generate 200 watts over a favorite 5 mile training circuit, I don't need a power meter to remind me how wimpy I am.
Same as the various online calculators for power/etc. These work best when wind is factored into one-direction segments and routes. Lends a dose of reality to my handful of top tens on Strava. Factor in the tailwind and my 300+ watts over 15-20 minutes turns out to be closer to 100 watts.
I've compared my Strava and online calculator power guesstimates against other folks my size who do use power meters on the same routes in the same or similar conditions. Close enough for my purposes. If it's off by 5-20 watts, no big deal. Until I can generate 200 watts over a favorite 5 mile training circuit, I don't need a power meter to remind me how wimpy I am.
#11
Senior Member
Join Date: Sep 2011
Posts: 4,764
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1975 Post(s)
Liked 232 Times
in
173 Posts
Are we talking about the ftp estimate from your power duration curve from actual power meter recording of your rides over a time period? If yes then I find its pretty close to 95% of my 20 min test so its pretty accurate.
Last edited by redlude97; 04-27-19 at 11:49 PM.
#12
Senior Member
Thread Starter
Yes, the FTP estimate. Not estimated power on segments. I tried my best to state this in the original question. I completely understand that the segment power is fairly useless. Really wondering thoughts on the FTP estimate.
#13
Senior Member
Thread Starter
I think Strava utilizes more duration points to analyze data than 8min, 20 min or 60 min measurement points that we're familiar with which is logical to me.
#14
Senior Member
Join Date: Sep 2011
Posts: 4,764
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1975 Post(s)
Liked 232 Times
in
173 Posts
I knew before even opening the thread the majority of answers here would be completely off base. Try the training or road racing forums, trainerroad forums, or r/velo
#16
Me duelen las nalgas
Join Date: Aug 2015
Location: Texas
Posts: 13,513
Bikes: Centurion Ironman, Trek 5900, Univega Via Carisma, Globe Carmel
Mentioned: 199 Post(s)
Tagged: 0 Thread(s)
Quoted: 4560 Post(s)
Liked 2,802 Times
in
1,800 Posts
The Elevate extension for Strava adds some potentially useful data including estimated FTP. Dunno if it's accurate. Probably depends on user-entered data. But it's been useful as a gauge of my progress on the same training routes I often ride. If the numbers trend upward, that's a fairly reliable indicator that I'm improving, even if the "FTP" number is relative only to itself within the context of the Elevate app.
#17
Senior Member
Join Date: Nov 2015
Location: Music City, USA
Posts: 4,444
Bikes: bikes
Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 2622 Post(s)
Liked 1,429 Times
in
711 Posts
Why would you trust that?
I recently popped off a big 90 day 1 minute PR and had a significant jump in FTP. Why? Because it was primarily an aerobic effort.
#18
Senior Member
Join Date: Sep 2011
Posts: 4,764
Mentioned: 28 Post(s)
Tagged: 0 Thread(s)
Quoted: 1975 Post(s)
Liked 232 Times
in
173 Posts
I mean I don't. That's kinda the point I was making, that whatever algorithms they are using dont take into account the entire power curve like WKO4/GC/Xert. Pretty sure strava just uses 95% of best 20 min effort which happens to be the way I test so its reflected in stravas estimated FTP
#19
Senior Member
Join Date: Jan 2014
Location: Southern California, USA
Posts: 10,475
Bikes: 1979 Raleigh Team 753
Mentioned: 153 Post(s)
Tagged: 0 Thread(s)
Quoted: 3375 Post(s)
Liked 371 Times
in
253 Posts
Estimate is not so good. It is better on hills. Then a real PM reading means?
I'm a bit cynical..
I'm a bit cynical..
#20
Senior Member
Thread Starter
So the Strava FTP estimator showed a significant increase immediately subsequent to your 1 min effort? That's really what I was curious about. On my account it's not using 95% of 20min. I think it's using a more complicated calc where it considers lesser duration also, but certainly wouldn't have thought 1 min efforts would impact the calc???
#21
Senior Member
Join Date: Nov 2015
Location: Music City, USA
Posts: 4,444
Bikes: bikes
Mentioned: 52 Post(s)
Tagged: 0 Thread(s)
Quoted: 2622 Post(s)
Liked 1,429 Times
in
711 Posts
So the Strava FTP estimator showed a significant increase immediately subsequent to your 1 min effort? That's really what I was curious about. On my account it's not using 95% of 20min. I think it's using a more complicated calc where it considers lesser duration also, but certainly wouldn't have thought 1 min efforts would impact the calc???
WKO4 showed an increase in modeled ftp after the effort.
Most everything impacts that model. Even 1 second sprint power affects the model.
#22
Senior Member
Join Date: Jan 2010
Location: TC, MN
Posts: 39,520
Bikes: R3 Disc, Haanjo
Mentioned: 354 Post(s)
Tagged: 1 Thread(s)
Quoted: 20810 Post(s)
Liked 9,456 Times
in
4,672 Posts
So the Strava FTP estimator showed a significant increase immediately subsequent to your 1 min effort? That's really what I was curious about. On my account it's not using 95% of 20min. I think it's using a more complicated calc where it considers lesser duration also, but certainly wouldn't have thought 1 min efforts would impact the calc???
#23
Newbie racer
Join Date: Feb 2018
Posts: 3,406
Bikes: Propel, red is faster
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 1575 Post(s)
Liked 1,569 Times
in
974 Posts
To everyone, rubi is right in the above posts.
Lots of the shorter stuff contains a pretty disproportionate amounts of anaerobic input. This contribution is different by person. It is probably worse among people like myself without a huge base/aerobic engine like the racer boys and girls who ride 3x the hours I do.
I find for myself, the 90 to 92% also is much closer. Forget 95%, unless you're a long course triathlete or time trial person only. Then you may be closer to 95% as your anaerobic contribution to 20min efforts probably isn't as much.
I tested at 300 for 20min months back. It took appreciable time after that to get my SS workout power for an hour up to 260 even. Why? I had gone through series of weeks of workouts that topped up the LT2 and anaerobic engines and essentially prep'd me for a great 20min test.
Even a week or so after that test, I couldn't do 260 for an hour! It took a few weeks of SS work to do so.
Most folks simply don't have the engine to interpolate short duration power to hour power without sorely over estimating.
Lastly...........the best indicator of performance is performance itself. You want to know.......try it and see.
#24
Full Member
I don't even have an option for estimated FTP...interesting.
I can tell you that it's estimated power on rides is awful.
To have a good idea of FTP you need to look at multiple data points, 5, 10 and 20 minute power. Or just do a full blown 60min FTP test, but that's not something I have any desire to do so I use estimates based on other data points.
I can tell you that it's estimated power on rides is awful.
To have a good idea of FTP you need to look at multiple data points, 5, 10 and 20 minute power. Or just do a full blown 60min FTP test, but that's not something I have any desire to do so I use estimates based on other data points.
#25
Me duelen las nalgas
Join Date: Aug 2015
Location: Texas
Posts: 13,513
Bikes: Centurion Ironman, Trek 5900, Univega Via Carisma, Globe Carmel
Mentioned: 199 Post(s)
Tagged: 0 Thread(s)
Quoted: 4560 Post(s)
Liked 2,802 Times
in
1,800 Posts
I think Strava offers that option to premium subscribers. Try the Elevate (formerly Stravastix) extension in Chrome. It adds lots of interpolated data/guesstimates.
I find it useful for longterm evaluations of my fitness and progress. 2018 was a rough year -- injuries and illness -- so it's been interesting to use the interpolated data to get an idea of my recovery. Just the past couple of weeks I've begun to match and occasionally beat my previous bests on 20-60 minute loop training circuits. Part of that is due to longterm physical therapy. Part is due to adding an aero bar to my old steel road bike for occasional use on flat segments; and getting a nifty old 1993 or '94 Trek 5900, which is much nicer for climbing. So my aero and weight cheats are probably skewing the interpolated data.
Yeah, a power meter would be more accurate. But I can't justify that when I struggle to average 160 watts over a 20-60 minute training ride. Just recently I've improved to averaging 175 watts (guesstimated). When I reach a guesstimated 200, then I'll consider a power meter. Well, maybe I'll rent or borrow one. I just can't see how having one would significantly improve my power. I'm never gonna see 300 watts over distance again, not at my age. But power meter data might offer either a nice attaboy bit of affirmation or, more likely, remind me that an aging human body is unimpressed by my rosy glasses.
I find it useful for longterm evaluations of my fitness and progress. 2018 was a rough year -- injuries and illness -- so it's been interesting to use the interpolated data to get an idea of my recovery. Just the past couple of weeks I've begun to match and occasionally beat my previous bests on 20-60 minute loop training circuits. Part of that is due to longterm physical therapy. Part is due to adding an aero bar to my old steel road bike for occasional use on flat segments; and getting a nifty old 1993 or '94 Trek 5900, which is much nicer for climbing. So my aero and weight cheats are probably skewing the interpolated data.
Yeah, a power meter would be more accurate. But I can't justify that when I struggle to average 160 watts over a 20-60 minute training ride. Just recently I've improved to averaging 175 watts (guesstimated). When I reach a guesstimated 200, then I'll consider a power meter. Well, maybe I'll rent or borrow one. I just can't see how having one would significantly improve my power. I'm never gonna see 300 watts over distance again, not at my age. But power meter data might offer either a nice attaboy bit of affirmation or, more likely, remind me that an aging human body is unimpressed by my rosy glasses.