I think that is part of why so many people get satisfaction, if not pleasure, from spending 5 or 6 hours per week maintaining or building physical fitness.
Fitness goals are simple and measurable. Furthermore, the relative mindlessness of it is a relief from the stresses that other life goals give us. For me, workout sessions lift me out of my mind into a pure animal zone of bodily effort. It is my form of meditation (if meditation implies emptying one's mind). Playing sports does something like that, as does sex. Regardless of age, don't underestimate the importance of sex.
I do not mean to say that sports are mindless, but once you get used to a sport, much of it is reflex. That is training: Down the line or cross-court.
Recreation: Hiking, sports, swimming, and general functioning/vitality are rewards for fitness.