My dad is in his 70's and goes to the gym nearly every day - sometimes twice! That's despite having cancer and chemo a few years ago and nursing my mum through hers until her death just over 2 years ago.
He's probably the opposite end of representative.
Most of the ones I know are generally fit and well and managing and not like I remember my grandparents at the same age.
I know a few who have health problems which are disabling.
Due to my age (40's) most of us now have parents in that age bracket.