Hurtin' butt after a few miles, might be due to:
*position of the saddle and bike fit. If possible to readjust it with nose either level with ground, or have nose, front of saddle, tipped abit up or down. Other option is have saddle moved forward closer to bike stem (which holds up your handlebars).

It depends which social groups I meet up with where people our age seem "older", in terms of how they look, dress and level of health. I have a friend just 1 yr. older than I and I worry about her because she looks 15 yrs. older than I. She had major surgery and number of problems related to her bowel and ovaries which has slowed her down. Unfortunately she is still eating a heavily based pork/meat diet, plus butter and sugars which isn't helping her. she tells me that walking up a hill for long does require effort and it hurts her feet to walk beyond half an hr.

I've known her for over last 25 yrs. She was completely different in terms of her health back then...meaning so much more active walking wise and healthier.