Children's natural play patterns provide opportunity for fitness development. Children typically do not care about the benefits of physical activity or the physiology behind the activities they perform, but they are very interested in participating in fun activities. Often curricula focus on how to feed children values that are important to adults. Instead of using forced activity, which is an adult model of fitness achievement, educators should engage children with enjoyable physical activity. Children are concrete learners, and the benefits of health-related fitness may not mean much to them. So teachers must connect the health benefits and cognitive knowledge so that students can relate and see the immediate personal benefits. The purpose of this article is to assist teachers in infusing physiological fitness concepts within the physical education curriculum through physical activity instead of classroom lecture. The approach uses the components of a workout and principles of training as the basis to address four major concepts. The article examines these concepts, provides examples of the skills and activities that students should perform, and shows how to engage children effectively in meaningful and enjoyable physical activity.