Used to run six miles every morning while active duty. I retired at 26 years with an injury that wouldn’t let me do that jog every morning. I have over those same years felt good during my morning PT an ran 12 with an 8 minute average a few times. Marathons ?
Nope...:o)
I’m 60 and I like to do about four and a half miles on the elliptical in a half hour. (Low impact). If you do it regularly, it’s not at all tiring. I imagine, gee, all have to do is repeat this seven times and I’ve done a 3:00 marathon.
Nope.
BTW, I remember my 25 mile march on the last week of basic. I was ok, but it took a lot more than three hours.