Abstract
BACKGROUND: Novel strategies to help adults with overweight/obesity increase motivation for becoming active are needed. This single-arm trial aimed to test the feasibility, acceptability, and preliminary efficacy of a 4-h acceptance and commitment therapy (ACT)-based workshop intervention for increasing moderate-to-vigorous physical activity (MVPA) among insufficiently active adults with overweight/obesity. METHODS: Participants (N = 41) received a 1-day 4-h ACT workshop followed by weekly e-mails and monthly phone calls for 3 months. The primary outcome was change in accelerometer-measured MVPA minutes/day at 3 and 6 months. Process variables (i.e., autonomous motivation, PA acceptance) through which the ACT intervention was hypothesized to increase MVPA were assessed via questionnaires. RESULTS: Participants completed 91% of phone calls and 75% of e-mail surveys. Acceptability ratings were > 4.5 out of 5 for "understandable," "useful," and "intent-to-use" on all intervention components. Participants on average achieved significant increases in bouted and total MVPA at 3 months that were maintained at 6 months. Participants also reported significant increases in physical activity acceptance and autonomous motivation, the latter of which related to MVPA changes. CONCLUSION: Results support the feasibility and acceptability of the ACT workshop intervention for promoting MVPA changes among insufficiently active adults with overweight/obesity. Rigorous testing of this approach as a low-intensity standalone or add-on intervention to increase MVPA is warranted.