Feasibility and Acceptability of a Co-Designed, Pair-Based Physical Activity Program for Autistic Adults

This study examined the feasibility and acceptability of a co-designed, Behavior Change Wheel-guided, pair-based physical activity (PA) program and explored preliminary changes in PA's level and motivation. A single-arm trial with pre-, mid-, and post-intervention measurements was conducted. Autistic adults participated with a chosen partner in a 12-week PA program that supported self-determined activities, goals, schedules, self-monitoring, fortnightly check-ins, and regular facilitator support. Outcomes included intervention acceptability, appropriateness, feasibility, adherence, and adverse events, as well as study feasibility indicators including consent, eligibility, recruitment, retention, data completeness and analyzability rates. PA and sedentary behavior were assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and a SENS accelerometer, and PA motivation was assessed using the Behavioral Regulation in Exercise Questionnaire-3 (BREQ-3). Four dyads enrolled. Participants rated the program as feasible, appropriate, and acceptable. Attendance and adherence exceeded the prespecified benchmark of ≥70%, and no adverse events were reported. One pair opted out of all non-measurement components after Week 1. The consent rate (29.3%) and enrollment eligibility rate (33%) fell below prespecified benchmarks, whereas recruitment and retention were 100%. Measurement completion rates met the benchmark (≥80%) at every time point. Analyzable rates met benchmark for SENS, BREQ-3, and the post-program acceptability/appropriateness/feasibility questionnaire, but not IPAQ-SF. SENS data showed reduced sedentary time and increased low-intensity activity at mid-program, with both returning to baseline at post-program. Most autistic participants showed higher self-determined PA motivation post-program. The program appeared feasible, acceptable, and appropriate for participants, but recruitment and onboarding posed challenges.