let stalk about xert

Pearl

THIS CHANGES EVERYTHING
www.xertonline.com

I've seen this pop up on strava once and a while and with a 4 week free trial, I downloaded it and synced it to my stuff. I'm slowly starting to enjoy geeking out over data, but not sure at what cost...

Whats strange to me is this list of Threshold, Peak, 2 Hour and Lower Threshold Power. Apparently its telling me my 2 hour power is only a 15 watt difference from my threshold? Does anyone swear by this or is it just another calculator spewing out numbers?
 

Pearl

THIS CHANGES EVERYTHING
I like finding the platform that says I’m the fastest regardless of accuracy, and stick with that one.

if you like free, check out intervals.icu
 

Steve Vai

Endurance Guy: Tolerates most of us.
Is it getting those numbers from your uploads? 15 watts is a bit close so 1 of the 2 is off. Your FTP might be higher than you think if the 2 hour is real.
 

icebiker

JORBA: Morris Trails
JORBA.ORG
Breath mints? Nah... This:
D660F028-C80F-47E9-A2D7-5866F9E06642.jpeg
 

Steve Vai

Endurance Guy: Tolerates most of us.
I uploaded my poop into it for shits and giggles. I've not done an FTP test in a long time because it's somewhat irrelevant in my discipline. 2 hour seems right. LTP is also in the ballpark.

Screenshot_20210324-073726_Chrome.jpg


The little spider web seems to confirm what we already knew.

Screenshot_20210324-074029_Chrome.jpg


IDK. Kinda neat but I probably won't sign up when the trial runs out.
 

Pearl

THIS CHANGES EVERYTHING
Is it getting those numbers from your uploads? 15 watts is a bit close so 1 of the 2 is off. Your FTP might be higher than you think if the 2 hour is real.
Oh no way I think my 2 hour is real. My FTP from a 20 minute test was 285 and they are saying my 2 hour power is 286. Explain that Xert!
 

Steve Vai

Endurance Guy: Tolerates most of us.
Oh no way I think my 2 hour is real. My FTP from a 20 minute test was 285 and they are saying my 2 hour power is 286. Explain that Xert!

It seems off. My 2 hour is right and my FTP is not. But at least my FTP is higher than my 2 hour, which it should be. I want to say it's 50 watts off. Let me find my peak 20 somewhere else to confirm. I don't usually follow anything under an hour.
 

Pearl

THIS CHANGES EVERYTHING
i think the "point" of Xert is that you dont have to do an FTP test, it just combs your data and shows you what it "should" be based on other efforts
 

Pearl

THIS CHANGES EVERYTHING
so I did a 4 minute max effort and my threshold power went up 8 watts. Just like that!
 

Steve Vai

Endurance Guy: Tolerates most of us.
After a bunch of rides, this APP is poop. I haven't ridden with a Power Meter and it just randomly fills in numbers with zero outside info. Somehow I averaged this wattage and hit this peak riding the canal on my singlespeed with no HR or PM?

Screenshot_20210403-194944_Chrome.jpg
 

Hakimaki

Active Member
As with all of these softwares like Xert, Golden Cheetah, WKO5, etc. You need to feed good data to get good output. Xert and WKO5 had my ftp 40 watts too low all winter until I did an all out Bear Mountain climb 2 weeks ago. Xert put me 3 watts shy of where I pegged my FTP to be by feel (verified by my numbers). So it was totally unreliable until it was.

Regarding the 2 hour power thing, it tells me there is 20 watt difference, so similar to yours Pearl. What I gather is that Xert is guessing what you can do, not what you've actually done. Can I do a 1x120 sweet spot effort? Hmm, probably not but maybe under the right circumstances and motivation. Can I train myself to do it? For sure. I recently did a 1x60 sweet spot interval which was doable and I probably could've kept going for another 15minutes.

Searching the forums, I came across a similar topic. An Xert Leader (assume he speaks for the company) had this to say:

"The 2 hour power number is derived by using a generalized endurance model, it’s not taken from MMP data, so there’s likely a good amount of variation between athletes. Remember that Xert is displaying the maximal effort that you can perform across the PD curve. For times up to about 60 min, this is rather easy to determine. Once you’re working beyond 60 min (or below TP), the rational for why you couldn’t keep pushing switches from muscular limitations (buildup of lactate/inorganic phosphate, calcium fatigue, etc.) to central limitations (motivation, willingness to suffer, etc), which is much more complicated to model. Perhaps we can do a little better job by including Endurance Energy as a 4th FS parameter, but still much work to be done on that".



Ref:
https://forum.xertonline.com/t/tp-and-2-hour-power-confusion/33776/6
 

Pearl

THIS CHANGES EVERYTHING
ya, im not as impressed with it either, or im just too dumb to understand the benefits it gives me. I'll stick with intervals.icu
 

Jmann

Never gonna let you down.
I had it crunch my numbers on a whim. It lumped in my non cycling activities as well, so definitely can’t be that accurate. Also I’ve been riding almost entirely sub threshold so far this year, so I wouldn’t have the data it needs anyway.
 

A Potted Plant

Honorary Sod
ya, im not as impressed with it either, or im just too dumb to understand the benefits it gives me. I'll stick with intervals.icu

Not sure on how to post this out there but I've been building an app off of strava's API to build my github. What analytical bits are you looking for?
 

Pearl

THIS CHANGES EVERYTHING
well my trial is over and while i didnt see any value in keeping it,

it was spot on with my estimate threshold power with the ftp test i did today, with my last 20 minute all out effort being 4-5 weeks ago. so for what its worth, it nailed that to the exact watt... so they may be on to something?
 
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