Adapting classroom-based physical activity interventions are critical for program feasibility and fidelity in low-resource elementary schools. The purpose of this pilot study was to use Replicating Effective Programs (REP) framework to tailor the Interrupting Prolonged sitting with ACTivity (InPACT) intervention and evaluate its effectiveness on program fidelity in classrooms within a low-resource school. REP was applied to adapt program packaging, teacher training, and technical assistance to disseminate Tailored InPACT, a 20-week intervention where teachers implemented 5 × 4-min activity breaks per day. Tailored InPACT was implemented in nine, 3rd-6th grade classrooms in one low-resource school in Detroit Michigan (80% qualified for free/reduced lunch). Intervention fidelity was measured via daily, weekly, and end-of-study self-report questionnaires and direct observation. Throughout the 20-week intervention period, 3rd-5th grade teachers achieved intervention dose (5 activity breaks per day at an average duration of 4 min 8 s). Sixth grade teachers did not achieve intervention dose as they were only able to implement 2 activity breaks per day at an average duration of 4 min 12 s. These findings suggest 5 × 4-min classroom activity breaks per day is a feasible dose of classroom activity that 3rd-5th grade teachers can implement in low-resource classroom settings. Additional adaptations are needed to maximize fidelity in 6th grade classrooms.
Keywords: Evidence-based research; Health promotion; Implementation science; Intervention study; Physical activity; Replicating Effective Programs framework.