If it's any comfort, same here. With me it's not the leg muscles but
simply running out of breath. My usual weekly valley run is around 40mi
and I have to get back up here, 1300ft higher with lots of up/downs. I
ride all through winter but can feel that the slog back up the hills at
the end is harder than it was just two years ago. Especially with cargo
which used to never bother me.
--
Regards, Joerg
http://www.analogconsultants.com/