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Indoor Cycling Vo2Max & FTP

R_Tellis
over 4 years ago

I had a cycling accident back in May and wasn’t able to run or bike much for awhile. When I did start getting back into riding I was sticking to the indoor trainer and taking it very easy so my cycling Vo2Max and FTP dropped accordingly.

Now that I’m getting back in shape the watts I’m putting out is going up but my Vo2Max and FTP aren’t. I know there was an issue in the previous firmware that was effecting running Vo2Max that was fixed but anybody noticing something like that with cycling?

My current Garmin FTP is 150w but I did a Zwift ride on Sunday where I averaged 187w for just under and hour and it didn’t update my FTP at all. Vo2Max stayed unchanged as well.

  • 0 over 4 years ago

    I’ll add that my heart rate zones are set properly and I’m using a Tickr X chest strap

  • 0 over 4 years ago

    VO2Max is calculated by comparing HR to power.

    With indoor cycling, HR is typically higher than cycling at the same power outdoors, as without the airflow of outdoors, your heart is working harder to dissipate heat so VO2Max will be lower indoors. Improving your indoor cooling setup (additional/more power fans) can help here.

    Garmin's FTP Autodetect doesn't look at 20 minute or 60 minute power. Instead it is really looking at LTHR and trying to associate it with a power number. Many rides don't generate enough HR data around LTHR to create an FTP estimate.

    You can edit FTP manually if you want.

  • 0 over 4 years ago

    I find Garmin's calculation of FTP to be unlike conventional calculations. Certainly it does not care much for 20 minute power or one hour power. It seems to include heart rate performance vs power to come up with its own version of the truth.

    For example, when you do a Garmin guided FTP test it will terminate the test when it's decided you've had enough rather than when you give up.

    I see Garmin revise my FTP, both up and down, whenever it likes, seemingly at random, and sometimes at odds with an improved 20 minute performance.

    As for VO2max, keep an eye on your performance condition as you ride. If you're in the positive you might expect an increased VO2max to result. If you're in the negative then possibly the opposite. Garmin appears to favour a rising power output over the course of a ride, but only if you keep your performance condition healthy. It seems to punish a falling power output, even if that's simply the nature of the (group?) ride (on Zwift)

  • 0 over 4 years ago in reply to eezytiger

    I understand what you're saying. I just find it weird that in the past Garmin, Zwift, and Training Peaks all regularly updated in sync with one another. They number's weren't always the same but at least each platform was recognizing changes in fitness.

    The ride on Sunday was pretty much a steady TT type effort without much variance in power output. Zwift saw it as an effort worthy of a 197 FTP, Training Peaks saw it as 178, Garmin didn't think it was worth mentioning even though I was above it's 150 FTP for almost an hour.

    Weird.

  • 0 over 4 years ago in reply to mcalista

    Thanks

    My indoor cycling setup is better than it has ever been. Recently added another high output fan in front and moved my older stand fan behind me.

  • 0 over 4 years ago in reply to R_Tellis

    I believe Zwift calculates FTP based on 95% of best 20 minute power. It won't care about your 60 minute performance.

    No idea about Training Peaks.

    And Garmin is just plain weird.

    You could try the FTP data field from Xert if you want an on the fly guesstimate of FTP across a broad range of variable efforts. That actually seems remarkably good and consistent with conventional tests, but more flexible.

    apps.garmin.com/.../a947db9d-abb6-4aea-818a-ee57fc369dbb