There is an increasing focus on health promotion in physical therapist research and practice. A clinical model (Health-Focused Physical Therapy Model) was developed for identifying major steps in the delivery of health promotion focusing on adoption of healthy lifestyle behaviors. One of the primary steps within this model is the design and delivery of behavior change interventions. Such interventions involve coordinated sets of activities that target change in a specific pattern of unhealthy behavior (eg, physical inactivity, smoking). This Perspective contends that the science and practice of behavior change interventions can be significantly advanced in the field of physical therapy (implementation science) through the integration of behavior change frameworks and techniques within the context of an experimental medicine approach for health behavior change. This perspective presents the integration of the Theoretical Domains Framework, the Behavior Change Wheel, including the Capability Opportunity Motivation-Behavior core system, and the Behavior Change Technique Taxonomy as a comprehensive approach for designing and delivering behavior change interventions in physical therapy. An experimental medicine approach is described, outlining a 4-step process in the design, delivery, and evaluation of behavior change interventions that can be applied to health promotion in physical therapist research and practice. The proposed integrative approach can advance public health and health promotion through healthy lifestyle behavior change in the field of physical therapy.