Garmin FTP estimate?

Hey Y’all :slight_smile: I just noticed that for the first time Garmin logged an FTP estimate in ‘reports’ at 201w. Since I started riding again in January, I haven’t seen it report a number. I got a new Garmin Fenix 5x a few weeks ago, but I only where it when I do a trail ride on Sundays, and I don’t have power meters on my bike. The rest of the week I’m on my Keister M3i trainer and I have a HR strap that pipes that into the bike, then to Sufferfest, and afterwards it shares the activity with Garmin. Last bit, it logged the FTP estimate on a day after a mountain ride, on a day when I didn’t ride at all.

So, how the hell does make that estimate lol? Just reading all past activity?

It’s noteworthy because it’s way higher than my 4dp I did at the beginning of June, but I’ve also improved a ton rapidly being relatively fresh at riding.

Anyways, any insight would be helpful :slight_smile:

Hi Ryan,

I used Garmin devices and their Connect-service for a long time and think I have a rudimentary understanding how it all works.

Most of Garmin’s health and fitness metrics are calculated on-device instead of in-the-cloud. This means you get more data by buying into the higher-tier devices or upgrading your older gear (always check which features are supported, if a certain metric is important to you).

In this case; buying a Fenix 5 “unlocked” your FTP estimate ( → Source).

It’s tricky to say which specific activity made this estimate possible, since Garmin uses (their now owned) Firstbeat Analytics and a lot of data points in your previous activities to come up with their numbers ( → Source).

I think your watch and Garmin Connect synchronized all activities including SUF (and possibly the last missing metric for the estimate) either on the day of the mountain ride or even a day after. Hence the delayed reporting.

Personally, I would trust the numbers from your Full Frontal Fitness Test and ignore Garmin’s guesses.

If your workouts are feeling too easy, maybe it’s time for a re-test on The Sufferfest.
Just ask yourself: Are-you-training-with-accurate-4dp-targets?

Anyway, just my two cents. I hope this helps.


Thanks so much, Pierre! Very helpful. I’m definitely due for a test and have the half-monty in 2 weeks as part of the all-purpose 12 week training, so looking forward to that. I feel I both have improved a bunch and maybe had been a bit conservative in going all out. I would love for my garmin number to be right, but feels a bit nuts at the moment :stuck_out_tongue:

Thanks for the source links!

1 Like

Half monty is great for establishing new FTP and MAP values. Sounds like you are heading in the right direction.

Testing takes practice. I’m riding on an indoor trainer for roughly two years and did a few Full Frontals in this time. I am slowly starting to get the hang of it. :slight_smile:
Keep in mind that every test is just a snapshot of a particular day. Sometimes we crush it, sometimes something goes wrong and we are not up to the task.

There is a big thread in this forum about the challenge testing provides ( → right here).

At some point your SUF numbers will reflect and even exceed what Garmin is guessing now. Be patient and enjoy the journey.

I know you will crush it!


Thank you for the encouragement! And for the thread link, I frickin’ love this forum :slight_smile: