The proportion of population « physically active » is based on the energy demands of a series of leisure-time activities that people participated in during the three months previous to the survey. Most scientific evidence is supportive of physical activity as a positive determinant of health. Greater health benefits can be achieved by increasing the amount-duration, frequency, or intensity-of physical activity. In Alberta and British Columbia, the 12+ years age group is far more active than their counterparts in other provinces.