I’ve been using the watch for training and racing for about 9 months so the VO2max numbers should be pretty stable*. The ftp estimate provided from the test seems reasonable to me, but I will try a ramp test on Tuesday to compare the results.
Once this data is obtained, the Firstbeat analytics engine identifies your FTP level by isolating the deflections in your heart rate variability that correlate to key indications of how your respiration patterns respond to the intensity of your activity."
This is the section that seems like a black box to me- I don’t know of any academic work that links ftp and hrv, and firstbeat obviously don’t want to publish it because it’s sensitive.
What I’m wondering is whether other people have experience with the Garmin/firstbeat test, and whether they found it to deliver reasonable estimates of ftp? Because if it does then it makes an attractive (quick and easy) protocol for repeated testing.
[asterisk] * some of the other Garmin/firstbeat metrics seem a bit inconsistent. For instance, my automatically detected threshold running pace is too slow while my predicted race performances are too fast.
The watch currently calculates threshold pace as 4:29/km based on a training session in mid October, however I ran a marathon at 4:22/km a couple weeks after that session and it didn’t update. Additionally, while estimating that my threshold pace is 4:29/km, it predicts I should run a 1:23 half marathon (3:56/km pace) and 2:53 marathon (4:06/km pace).