The garmin body battery is only accurate-ish if you wear it all the time. In my case, I only wear it from time to time or when out on a run, so the algorithm seems to think I sit on my ass for 4 days in a row and then do a hard effort, hence the 4 or 5 day recovery time
Also, holy crap, a 90 tss 1 hr workout is brutal!
I go by a mixture of TSS, CTL and ATL as far as planning workouts, but nothing is more accurate than how I’m feeling. Anytime I’ve had a failed workout, I knew it wasn’t gonna go well right from the start. Don’t need a device or number to tell me it ain’t gonna happen!