It seems that certain breeds of dogs are totally happy to be inactive, and some that go at least a little crazy if they don't live on a farm where they can run.
I have fibromyalgia, and it manifests itself largely with an intolerance of more than 15-20 minutes of aerobic activity, depending on the day. I used to be an athlete, so it is particularly painful to not be able to exercise.
I know people who choose not to exercise, I also know others that I think would go crazy if they couldn't exercise. I'm the only person I know that's is unhappy because I CAN'T exercise more (without expensive treatments and discipline).
It will probably take thousands of dollars of massage treatments & rigorous discipline with regards to diet and tracking activity to get me to the point where I can exercise at least 20 minutes, 5 times a week.
I'm looking for some insight as to whether exercise could be that important for happiness for some.