ScotchMonkey: I'd recommend exercise to anyone in order to maintain a sense of happiness (and everything else that comes with exercise). Research shows that the less active are surprise less happy, no matter their particular place in life.
That doesn't prove exercise makes you happy, it might also mean less happy people tend to exercise less. With all those happy people exercising, I imagine they get much more joy out of exercise than I do. When I did exercises, I was always relieved when I stopped doing so and had more time and energy left for the things I do care about in life.
Also, when I ended exercising, it usually was for depression (caused by an overly busy schedule) kicking in when I had to go off to fitness or later running, it was the depression that had a negative effect on exercising, not the other way around (like what they say, exercising having a positive effect on depression). Most people are now who are happy with sports, don't feel happy sporting because they sport, but because they
like sporting. If you don't like sports, it doesn't do shits for you, it just feels like another obligation dragging you down.
There were things I liked about sporting, but it wasn't the sports themselves, it was the peripherals. With fitnessing, I finished off the day with a cooking group. When the time of fitness was changed to an earlier time, so I couldn't follow it up with coocking and eating together, the joy was lost. With running, the fun was being in the woods. When the coach that normally took people into the woods went on to other work and the remaining coaches stayed on the boring running track, joy in running was lost as well: the joy was being in the woods, not the running. And I can have a far more enjoyable time in the woods walking, than running through it watching my pulse on the chronometer.