Highly recommend and can't see a bigger root cause for the current human predicament.

Not in aviation anymore, but luckily that practice seems to be forgotten now?

I did this on purpose this spring.

I had a shitty winter in terms of endurance and was pretty much starting from the gutter in February. Spring and early summer we're stressful so I did mostly Z1/LSD cycling in the form of extended commuting from work to home. Nothing excessive though as stress was plentiful.

The estimated fitness or the Garmin estimate didn't budge much.

Once vacation started I kept this on for few weeks to recover and after that added few harder sessions in a two week period. Few weeks after this I felt the change and Garmin also estimated 6 mil's of added VO2MAX in a week.

Don't care about the metrics, but the added QOL from this and now I hopefully have a structure for the coming winter not to lose as much of this as the previous.

Here's a nice summary. Haven't read the book yet though it's on my list.