Even two years ago I got winded walking up the hill I affectionally have named the Matterhorn on one of our properties - now I could run it without difficulty. I was what I thought was reasonably active - now I am very active.
Face it, when we aren't riding but just driving to work and back everyday with the biggest excercise being finding the remote - we are barely alive.
I have frequent visitors to the fincas - they are warned about me by the office staff - who then try to get me to take it easy on them. I warn people that they will not keep up and will have to let me know - they don't believe it - until the first hill.
Part is the climate - only mad dogs, englishmen and cyclist go out in the tropical noon day sun. And farm laborers. The average person in the USA isn't just overweight - they are dreadfully out of shape - and no, round is not the shape I am referring to.