I'm 63, and still a decade away from 70 to 80, however life has dealt a few challenges my way, including a partial stroke at 54. I have more time now, so I used to jog 4 laps of a footy oval every weekday, then walk totalling minimum 20,500 steps every day. Except weekends. I felt my body needed to recuperate. My maximum walk has been 103,556 steps in one day, but I have been eyeing the possibility of doing 164,000 steps in 24 hrs. But even with the 75, 80 and 103,000 steps I've lost a few toenails, and there has been distinct probability of stumbling and hitting my head on the pavement. Remember I've had a partial stroke, so my balance is affected when I walk. Having said that, recently I was getting random sharp pains in the knee joint when jogging. And when I saw the GP he made an appointment for me with an orthopedic surgeon. After ~ 6 months wait I finally saw the orthopedic surgeon , who said I have the beginnings of arthritis on the knee joints. Hence the random sharp pains. He suggested swimming, walking, or cycling instead of jogging. So I will look into cycling as I already do walking. Swimming can get expensive and added to that, there is other people who may have a cough or bug which I may catch. Because of my balance I'll get one of those indoor bike trainer thingies. With these balance nor traffic will neither be an issue. But I'm in the middle of change of address at the moment so it will have to wait. Walking for now.