It could also very well be that those participants in the study who didn't "exercise" were lonely, were more or less alone or single, had no one to go take a wa

It could also very well be that those participants in the study who didn't "exercise" were lonely, were more or less alone or single, had no one to go take a walk with, have lost their closest relatives, have lost their significant other, etc. All those could factor in as much if not more than the "exercise". (and hence spend much more time indoors, probably watching the telly, and then things go from bad to worse in old age as health problems cascade) And I quote "exercise" because it's not clear from the article if it's something like gymnastics, or the participant reported 30 min of daily walking and other activities like cycling. Point being, you could be unhappy and exercise a little bit every day and still be worse off than someone who's happy and loves to sit and watch the bird sings. Who knows. I'd wager these days the quality of our food, and the bonds we have with people around us is far more incidental on our lifespan. Here I am thinking of the less explored perspective: https://www.theguardian.com/commentisfree/2014/oct/14/age-of-loneliness-killing-us https://www.theguardian.com/commentisfree/2014/oct/14/age-of... Quoting > "One of the tragic outcomes of loneliness is that people turn to their televisions for consolation: two-fifths of older people report that the one-eyed god is their principal company."