In Phase 2, we will conduct a fully powered optimization trial. We will enroll 192 participants, planning to role approximately equal numbers of participants in both sites. In both phases, all participants will receive the core yoga intervention (12 weeks of weekly manualized yoga classes), with random assignment to the 4 key intervention components. Participants will be patients enrolled in methadone (MMT) or buprenorphine/naloxone (BUP) treatment with chronic pain. Enrollment period for this phase will last approximately 2 years.
Phase 2 - Multiphase Optimization Strategy (MOST) Optimization Phase:~To conduct a factorial experiment that will allow us to evaluate the impact of each of the 4 intervention components on yoga dosage received. We will enroll a total n=192. All participants will receive the core yoga intervention, with random assignment to the four intervention components outlined above.~Use results from Phase 2 to choose an efficient combination of intervention components that, together with standard yoga classes, maximizes yoga dosage.~Examine mechanisms by which components are hypothesized to work.