This perspective outlines the theoretical basis for the presentation with the same name as the second part of this title, which was given at the III STEP conference in July 2005. It elaborates on the take-home message from that talk, which was to promote activity in children and adults with cerebral palsy and other central nervous system disorders. The author proposes that the paradigm for physical therapist management of cerebral palsy needs to shift from traditional or "packaged" approaches to a more focused and proactive approach of promoting activity through more intense active training protocols, lifestyle modifications, and mobility-enhancing devices. Increased motor activity has been shown to lead to better physical and mental health and to augment other aspects of functioning such as cognitive performance, and more recently has been shown to promote neural and functional recovery in people with damaged nervous systems. Although the benefits of fairly intense physical exercise programs such as strength training are becoming increasingly well recognized, few studies on the positive effects of generalized activity programs have been conducted in individuals with cerebral palsy. More research is needed and is currently under way to design and test the efficacy of activity-based strategies in cerebral palsy.