Values-based and acceptance-based intervention to promote adoption and maintenance of habitual physical activity among inactive adults with overweight/obesity: a study protocol for an open trial.

INTRODUCTION: Despite the importance of regular moderate-intensity to vigorous-intensity physical activity (MVPA) for health benefits and long-term weight management, current comprehensive lifestyle interventions have focused on providing MVPA prescriptions and goals but with only minimal and intermittent focus on psychosocial theoretical constructs and novel strategies, perhaps explaining the often modest impact on adoption and maintenance of higher levels of MVPA. An intervention based on acceptance and commitment therapy (ACT) targeting the increase of values-based autonomous motivation could improve the adoption and maintenance of habitual MVPA among insufficiently active overweight or obese adults in a brief intervention format.

METHODS AND ANALYSIS: The overall aim of this study is to develop and test the feasibility, acceptability and preliminary efficacy of an ACT-based brief workshop intervention for increasing bouted MVPA for inactive adults with overweight/obesity using a single-arm design. A total of 48 inactive adults with overweight/obesity will be recruited and attend a 4-hour, ACT-based workshop followed by weekly emails and monthly phone calls for 3 months. The workshop will teach values clarification and acceptance-based skills to increase values-based autonomous motivation and bouted MVPA. Participants will self-monitor minutes of MVPA and personal values and report on progress via weekly emails and monthly phone calls. Assessments will be conducted at baseline and at 3 and 6 months.

ETHICS AND DISSEMINATION: Study procedures have been approved by the Institutional Review Board. Consent is given in writing and in person. Data collection and storage separates study data from personally identifying information. Two safety officers who are not connected to the study monitor study progress and participant safety.

TRIAL REGISTRATION NUMBER: NCT03565731; Pre-results.