Six months ago I returned to cycling after years off. One thing I note, besides even more joy in riding now and the fact my once tricked-out bike is now a museum piece, is the need for a longer warm-up period on each ride. 5 miles is good, but I feel even looser and ready to "seriously" cruise at 10 miles. I notice my younger fellow riders clip in and are over the horizon while I'm still clearing my computer. Either it's their youth or my stiffer joints.
I also notice that if I save something to eat during my 3-4 miles of cool-down I seem to feel better later in the day....maybe just a misperception.