Despite the recognized health risks associated with physical inactivity, most Americans are not active enough to achieve health benefits, and many report no planned physical activity at all. The Surgeon General's report on physical activity and health and several research studies have provided evidence that most Americans do not exercise and are consequently at risk for numerous health problems. School physical education has been challenged to produce programs that will develop positive activity patterns that youths will carry into adulthood and to foster dispositions that value physical activity. This article (the 2004 Alliance Scholar lecture) explores methods that teachers can use to create an environment that will encourage students to choose physically active lifestyles.