Great! Weird isn't it, how the leg muscles seem to pull on everything below the shoulder blades. It's called the "posterior chain," all connected. My wife and I did 50 miles on our tandem yesterday, with a lot of that being "spirited riding." Cars would pass us, seeing only a bicycle, not having any idea we might be doing 25, and then having issues with the oncoming. I have built-in reflexes to head for the ditch in the event of a head-on happening in front of us.

Back hurt like the devil yesterday, but OK today, glutes still a bit sore today. I think we'll take an hour's walk, today being unusually sunny.