As I started riding again in my late 50s I have found that I need to dismount and walk a bit on a long ride. So, if my ride is longer than 15 miles I get off the bike every 10 miles---religiously-- no matter how good I feel. I don't sit or stand around. Sometimes I only walk a few hundred feet sometimes a quarter mile. I always feel better when I get back in the saddle. I also will stretch, especially for calf/achilles tendon several times during a long ride.

I never had to do this stuff when I was young, but now it works very well to keep me riding. It is one reason, at my age, that I almost always ride alone. Most younger riders want to keep going and have no patience with my walking every 10 miles.

Something different might work for you. Just remember that older riders need to adjust how they use their aging body.