Im 76. A lot of others that post here are like me. We have health such that physically we are much younger than our years. Granted we are very fortunate to have good genes, but keeping active thru cycling helps keep us that way. As I have stated here many times, if you set you rust. Never give up, do everything you are physically able to do.
I might add that cycling is a great way to exercise since it doesnt pound the heck out of your body. And-----------I have to add that riding a bent as I do, I dont suffer all the pain and discomfort of a DF bike. Bents equal all gain and no pain.