I don't train as hard as CB but still get, not exactly pain but discomfort once mileage ramps up during warmer weather. What helps quite a bit is compression tights or socks. I attribute it all to an inability to recover quickly and compression wear does the same job as a compression suit does for a fighter pilot, improves circulation. Diabetics also experience improved circulation with compression socks.

At 77 y.o., I do some work with dumbbells for upper body strength but the majority of work consists of some yoga moves to maintain flexibility and a strong core and knees.