the majority of those are at threshold, just mentally ignore the three non-threshold (IF of 0.77, 0.73, 0.84) workouts. Therefore all but three of those rides are basically at or near FTP, and with basically no decoupling. IMHO the data tells a story.
In other words, all but three are:
- at same relative intensity
- on the same course and time is relative to the amount of headwind
- over a period of many months
- over a period of increasing aerobic capacity (late 2016 lower aerobic capacity compared to March/April 2017)
Putting decoupling into a zone bucket, workout by workout. Workouts with a low VI, say 1.05 or lower, means it was close to a ‘pure’ zone workout for that segment:
my n=1, after establishing basic aerobic fitness my decoupling is usually below 5% on zone2 / zone3 / zone4 workouts. My hypothesis for the negative numbers is that the warmup includes a hard effort a few minutes before the start of the segment, and heart rate settles down over the first few minutes of the segment.
I’ve seen similar trends on other workouts, with a longer warmup and then a long steady tempo effort.
All of that is a long winded explanation with empirical data, that I’ve found little value to using aerobic decoupling as a general purpose metric during a season and across seasons. However it does help me after an off-season break.
Your Mileage May Vary (YMMV).