According to Steven Blair, More than sixty percent of American adults do not get the recommended amount of physical activity. In fact, twenty-five percent are not active at all. Nearly half of all American youths 12-21 years of age are not vigorously active on a regular basis. Moreover, physical activity declines during adolescence. Eating less and eating sensibly is only one half of the fitness balancing act; physical activity is the other -- very important -- half of the equation (Blair 1 ). For people to become physically fit, they ne ....