A tip on the HIIT I didn't know about until recently. If you want to supercharge the session, toss in a reasonable length SS effort after your HIIT sets. 5min minimum. 10min preferable. It'll suck. But it's a different energy system.

Something about the HIIT mobilizing some kind of fat energy in your body during the tougher HIIT part. Then actually using some of it up with the SS at the end instead of it just reattaching somewhere.

That sounds very unscientific, but that's the gist of what was in the podcast.

I think the fasted rides may be more about teaching your body to operate efficiently and powerfully using fat more than getting skinnier. Not totally sure, but thought so.