I'm 74 years old and there have been very few periods of my life that I did not have at least one bicycle. Even in the air force I had bikes including one very poorly made machine in Vietnam. Needless to say that one was confined to getting around on the base at Bien Hoa. Currently have a commuter for the 7- mile ride downtown to a volunteer job 2 or 3 days per week and a hybrid for general riding. Yes, endurance has diminished over the years and I last "rode my age" 4 years ago. Between aging and the increase in traffic around this growing metro area, I ride less cross country and more on MUP's and city streets. Riding a bicycle still seems somewhat magical to me and I often sort of zone out just gliding along with so little effort. Of course the hills are getting steeper, but the shifter hasn't bottomed out on me yet.