In riding from Sanderson TX to Del Rio TX today, I broke my previous personal best of 120 miles in one day. Furthermore, that earlier best was done on a lighter bike, with no gear of any kind, as well as no wind, no hills, and perfect concrete. Today involved high winds, rolling hills most of the way, and chipseal for most of the ride.
I didn't even feel unusually sore at the end.
In terms of physical fitness I'm considering this real progress.