As an athlete (or so I like to think), somewhat of a scholar, and mostly-active religion-practicioner I have come to relieze through my own experiences and through the sound of "The Biggest Loser" coming from the next room the infallibility of fitness as a self-perpetuating motivational tool that promotes excellence. Fitness however does not simply refer to having low blood pressure or being able to run a sub-8 minute mile, but rather the proficiency in a field that can lead to a deep sense of fulfillment in society as well as in oneself. The three most foremost fields of fitness that come to mind are mental, physical, and spiritual fitness.
In terms of physical fitness, as in any other kind, goals are varied greatly depending on the individual's desires. An example that relates directly to me, a sprinter in pre-season track training, an hard workout followed by an honest day's work in the weightroom lead to a sense of self-fulfillment knowing that I am improving my own abilities as a runner, and this increase in personal physical fitness has societal benefits because I am helping to encourage the members of my relay team to do the same, as they inspire me so that we might work toward our common goal of earning All-American honors.
Doing homework (GASP!), crosswords, sudoko, debating, conversing, reading, or simply thinking to oneself are all ways to increase mental fitness by creating new connections of neurons in the brain to allow for the flow of new stimulating ideas to pass through one's mind. These new ideas in one's own mind can be used in society by politicians and lawmakers in crafting new effective policies, by authors in the writing of interesting enlightening works and by teachers to better instruct their pupils on the subject matter that will shape them as citizens of tomorrow.
Spiritual fitness whether it be through organized religion or personal practice can enhance both physical and mental fitness because it can offer motivation to offer one's gifts up to a greater good or to improve one's relations with the world around them the best they can. Spiritual fitness is best attained through personal prayer, meditation, reflection coupled with community practice and sharing of ideas to spread messages of peace and love. Spiritual fitness should not be mistaken for self proclaimed "Good-(insert religious group)" because Spiritual fitness transcends religion, and while may be incorporated into a particular faith as it is with my own, does not make one worship better than another. That is a doctrinal argument, not a spiritual argument.
