I do a minimum of 5-10 hours a week of aerobic exercise (mostly cycling), to make time for more, I'd either have to quit my job or board the kids somewhere. I

I do a minimum of 5-10 hours a week of aerobic exercise (mostly cycling), to make time for more, I'd either have to quit my job or board the kids somewhere. I also have some anecdotal evidence. My father was always an avid cyclist as well, until his hip joint wore out. He had to give it up, and in the space of a year turned into an old man. I'm sorry, unless something else kills you in your prime, it will happen to all of us sooner or later.