I am the same age/BMI as you.  In fact I am fitter and in better shape now than I was at 25.  Yeah I have to work at it more, but only slightly.  Yeah I maybe feel slightly less flexible now, but only barely.    As long as we continue to mitigate the effects of aging by working out/ being active, I think we should all be able to feel great well into our 70's and beyond if all goes well.