Abstract
Many adolescents, particularly those diagnosed with autism spectrum disorders (ASD), fail to get ≥ 60 min/day of moderate- to vigorous-intensity physical activity (MVPA), in line with the World Health Organization's guidelines. Whole-day interventions (i.e., interventions implemented throughout the day) can increase physical activity (PA) levels throughout the day to meet these guidelines. However, there are no known behavior-analytic studies examining the effectiveness of whole-day interventions for increasing PA levels in adolescents diagnosed with ASD in both the short- and long-term. Two adolescent boys diagnosed with ASD and their mother tested the effectiveness of a parent-implemented multicomponent intervention package comprising progressive goal setting, feedback, reinforcement, and self-monitoring to increase whole-day step count. The participants increased their daily step counts to 14,000 steps (which translates to ≥ 60 min/day of MVPA) by the conclusion of the intervention, thus meeting or exceeding PA guidelines. The family then adjusted the procedure to better meet their lifestyle needs, resulting in long-term maintenance of PA above baseline levels at 6- and 11-months post-intervention for one participant, and 11-months post-intervention for the other participant. This study therefore shows the importance of tracking long-term changes in outcomes and understanding factors influencing the sustainability of these outcomes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40617-024-00970-w.