Methodological Overview of A Self-Determination Theory-Based Computerized Intervention to Promote Leisure-Time Physical Activity.

OBJECTIVES: To provide a methodological overview of a computerized intervention to promote leisure time physical activity (PA) and to apply self-determination theory (SDT) to PA initiation to better understand the psychological mechanisms underlying PA frequency, intensity, and duration in previously-sedentary individuals. DESIGN: Based on SDT, two computerized personal trainers were developed for use with sedentary young adults. One personal trainer was designed to be need-supportive, empathic, and structured while the other was designed to be more controlling, evaluative, and judgmental. METHOD: Participants are randomly assigned to work with either the need-supportive or controlling computerized personal trainer. They complete a series of 7 weekly training sessions. In between training sessions, participants complete daily records of PA behaviors and experiences including autonomous self-regulation and perceived competence for PA and PA frequency, intensity, and duration. POTENTIAL CONTRIBUTIONS: The design of this intervention and its theoretical basis have important implications for advancing the field of exercise science specifically and health behavior change more broadly. Computerized interventions have the benefit of standardizing intervention content as well as reducing clinical contact burden for practitioners. Daily recording procedures reduce the likelihood of retrospection bias and allow for the modeling of (1) daily fluctuations in PA behavior and (2) the psychological mechanisms believed to be involved in PA behavior (e.g., autonomous self-regulation). Finally, as a broad theory of human motivation, SDT is uniquely positioned to offer explanations for the conditions that are likely to promote both the initiation and maintenance of health behavior change.