In conclusion, the WalkIT-A study provides partial support for the efficacy of adaptive goal setting interventions for increasing PA in adolescents. Through a single-subject, ABA study design, similar trends in PA behavior were identified in three sedentary adolescents. Despite differing lengths in the number of days each participant spent in each study phase – baseline (A1), intervention (B), and withdrawal (A2) – the general patterns of step count and MVPA were similar across subjects. Both steps and “very active” minutes increased from the baseline period to the intervention, followed by a decrease in steps upon completion of the intervention into the withdrawal phase. This provides support for the positive impact of the intervention on increasing steps. Though future research should aim to validate these findings through stronger intervention components, expanded intervention periods, and novel motivational components to account for PA “drop-off” midway through the intervention, the use of adaptive goal setting combined with incentives can be an effective means to incite PA behavior change in adolescents.