Post up if you had this happen and why you think less weekly TSS can yield a better FTP result. Today I just had my highest FTP result this year; my 5th ramp test in 2019. (testing conditions all the same). This is following a low weekly average TSS around 250 the last 6 weeks by simply doing Base 1 low volume verses my summer weekly TSS of around 400. So, after a solid structured season of TR Base and Build workouts (mixed with outdoor rides), I take the usual Fall break, do Base low volume 1 (no outdoor rides) and get my best FTP result all year. I’m happy about it but must admit that I’m kinda confounded that I can see an FTP increase from the low volume plan versus my fitness gains from some hard, long outdoor group rides in the summer. Theories on why, your experience, please post.
This actually makes perfect sense. Extra work is only good if you can recover enough to allow your body to make the appropriate adaptations.
Too often, we see people with eyes bigger than their stomach (to steal the metaphor). They crush themselves, get too little rest/recovery for the work they did, and fail to fully absorb that training. They are shocked that all their suffering leads to worse results, rather than better.
That is the reason the TR guys always recommend starting with less than you thing you can handle for volume and stress. Make sure you can really handle (and adapt) to that load. And only then, consider adding more Z2 Endurance work to stretch yourself. If that goes well, consider jumping up in volume, but only really needed if you have maxed your potential with the current load.
Back to your main conclusion, less can be more… especially if the more is too much. 
Nothing to add, but to wish you a happy birthday, Chad!
Thanks! 
Been a great one so far. Dinner tonight with the family, so headed even better 
Nice thoughts Chad, as usual… and sounds like a happy birthday is in order!
Much appreciated
Nope, the 400 TSS is with a big weekend group ride of about 200+ TSS (basically like a race for me but we take breaks) then 1 or 2 low or mid volume build workouts during the week.
I actually saw this too. Came off general build mid volume, did my A event, and felt totally cooked. Bounced back down to SSBMV1 and saw a 21 watt jump in my FTP. I think one upside of revisiting base after a build phase is that it gives you time to recover and absorb the work.
To add a bit, the difference between short structured workouts inside and long unstructured rides outside is likely a big factor. The whole “all TSS is not created equal” mantra likely applies here. You are likely getting more direct and effective training stimulus via the shorter works, that are more targeted to specific energy systems.
So many group rides are a mess of the gray zone (to use that bad phrase) that is not really “training” in the sense that it is rarely targeted at anything other than measuring fitness and egos. I love a good group ride, but proper training it is not.
There is real value in those rides in the opportunities to ride against stronger riders, deal with the unknowns of waiting (and hoping) for that idiot at the front to let up so we can recover a bit. I find those rides are better for me from the mental stress aspect as I fight the internal desire to slow down, but the competitor in me wants to push on. That push/pull is one of the great reasons to include these rides as part of training.
But looking at the whole picture, there are great gains to be had from that lower TSS if it is the right TSS (via volume and application) to stress your body. Coupled with the recovery above, you can gain a ton from that compared to “harder, but looser” group rides that appear to be “better”, but might not be.
Agree with everything you said. A big take away for me is that there is some good fitness to be gained from simply doing the “easier” SSBLV even for a seasoned cyclist. If I didn’t enjoy group rides so much I would probably do 95% of my training indoors and be super strong for the rides I choose to do.