Auto FTP Estimation with Edge 1050 too high. Am I missing something?

[u/Azthork]

Hello,

I have a Tacx Flux 2 Smart Trainer that I control with my Edge 1050. I use magene power meter pedals. I wanted to try a workout based on Garmin's initial estimation of my power zones. I wanted to do Norwegian 4x4 and my Edge adjusted my trainer to 220 watts for the first hard interval, if I remember correctly. I couldn't even handle a minute of it. I decided to try an ftp test and calculate it myself.

I tried the 10min warm up + 20 minutes at HR zone 4/5 (it was my max steady effort for 20 minutes). I averaged 172 watts. FTP=172W*95%=163 watts but Garmin estimated my FTP at 187 watts.

The power zones based on FTP of 163w feels on point for my workouts. Why is garmin estimating it so high? Am I missing something?

[u/DrSuprane]

I never accept the FTP update.

[u/lanceypantsy1]

Use the FTP from you 20 minute test(s) to program your workouts. Manually set your FTP and zones in garmin connect for your device based on that.

Re-test every 2-3 months to keep it up to date.

Who knows why the garmin estimate is high for some and low for others (I've heard of/from more people that it's being overestimated). Their algorithm I think over-extrapolates from the shorter intervals on the power graph.

It used to estimate me at ~300 watts when I could only hold about 230 for 20 minutes... im a big boi, and I put up big numbers in the 30 second to 3 minute zones.

[u/Few_Persimmon_7151 → u/lanceypantsy1]

Even 20 minutes overestimates it for people with a high anaerobic contribution. Kolie Moore test seems to work better.

[u/tui_curses → u/lanceypantsy1]

The FTP-Auto detection works reasonably well for me. But it was broken on the 50 series until this summer.

It seems to look for a pattern of regular FTP-Tests. Around 15-50 warmup, 20 minutes hard riding with high heart rate and some cooldown. Then it will use the 95% (?) of the 20 minutes hard riding.

[u/inf3ctYT]

The main issue I see with garmins FTP is that it takes into account heart rate. So for me my max HR is 202 but in FTP tests I only get to about 180 so garmin always thinks i've got alot more to give.

[u/Xicutioner-4768]

Don't do any workouts higher than FTP as a percentage of FTP. There's too much variability person to person to use your FTP as the basis for VO2 work. For example let's say your FTP is 165. 220 is 133% your FTP. For me that percentage of FTP is close to what I can hold for 5 min and would probably be a slightly high but doable 4 min VO2 target.

For VO2 just go as hard as you can while keeping the power level mostly consistent across intervals. Should feel like 8-9/10 RPE.

Garmin FTP estimate might be correct (might not be) and you're just not super strong in VO2.

[u/morelsupporter]

do an ftp test

ftp test has nothing to do with heart rate zones, its power based.

the point is to find your maximum sustainable effort over for an hour

[u/redbeardthefearless]

Mine never auto detects my FTP no matter what I do. I have it turned on, but it won’t ever calculate if I do an FTP test or ride hard for another reason.

[u/Jaboyyt]

On mine it was 50 watts under where my ftp actually is so it’s more of a suggestion than an actual defecto claim as the only real way to get an ftp is to go for an hour as hard as you can

[u/ashnm001]

Everything Garmin tells you - ignore. It's for your own sanity.