Getting active no doubt increases life satisfaction as well as life span, and supporters of the activity theory expanded the findings with studies of their own [source: Centers for Disease Control and Prevention]. A 1982 study of retirement communities showed that how seniors got active mattered as much as whether or not they were active. Activities that were informal and less structured increased quality of life a lot; solitary activities weren't shown to improve satisfaction and organized or formal activities actually showed a negative impact [source: Longino]. Other studies showed the opposite, that doing things alone, participating in organized activities and even being inactive can lead to happiness, depending on the person [source: Roy and Russell].
So which is it? Maybe keeping in mind that the activity theory is a "psychosociological" theory, one concerned more with psychology and social interactions than actual activities, helps put it in perspective [source: Encyclopaedia Britannica]. It is really helpful to look at how staying active impacts the emotional health and self-esteem of seniors, but it isn't really a guide to exercise or ways to engage: It just confirms that including both makes life more enjoyable.
If seniors have lived to be "seniors," they probably have their own likes and dislikes or are finding new ones. Just as with any stage of life, getting involved in an activity you don't like won't benefit your overall satisfaction; it may even make you grumpy and less likely to look forward to doing it at all. Same goes for spending time with individuals or groups that don't share your interests or move at your speed. It will keep you busy and active, but not very self-satisfied or even a positive part of the group dynamic itself. If you get a lot of enjoyment and peace out of solitary activities, do some of those, and if you thrive in group environments, dive into those.
Maintaining who you are from age to age while being active has tremendous emotional and physical benefits, but you know more about what activity does your body good than any theory of activity [source: CDC]. Getting moving in order to live longer can complement who you already are and what you already like to do or want to try.