Physical educators have purported to teach children to be physically active and to promote their fitness. To achieve these goals, children should regularly experience moderate-to-vigorous physical activity (MVPA) during physical education lessons. For the purposes of this review, moderate physical activity is that which elicits a heart rate of 50% of maximum heart rate reserve (MHRR), moderate-to-vigorous activity elicits 60% of MHRR, and vigorous activity elicits 75% of MHRR. Duration criteria were set at 50% of lesson time or 20 min. The majority of lessons described in previous reports failed to achieve these criteria, although problems were noted in method and analyses of data. Lessons with physical activity as a direct goal have been successful in increasing MVPA. A greater focus on physical activity is required in the planning and delivery of physical education lessons if the physical activity and fitness goals of the physical education curriculum are to be met.