A phone and text message intervention to improve physical activity in midlife: initial feasibility testing

Background: Physical activity during midlife (ages 45-64) plays a major role in the prevention of chronic and serious medical conditions. Unfortunately, many midlife adults struggle to be physically active in the setting of low levels of psychological well-being and the management of multiple confluent sources of stress. Effective, scalable, midlife-specific interventions are needed to promote physical activity and prevent the development of chronic medical conditions. Objectives: In an initial proof-of-concept trial, we assessed the feasibility and acceptability of a new, midlife-adapted, phone- and text message-based intervention using positive psychology (PP) skill-building and motivational interviewing (MI) techniques. We secondarily analyzed post-intervention changes in accelerometer-measured physical activity and self-reported outcomes. Methods: The PP-MI intervention included six weekly phone sessions with a study trainer, with completion of PP activities and physical activity goals between calls, and in the subsequent six weeks briefer phone check-ins were conducted. Text messages over the 12-week intervention period were utilized to support participants and identify barriers to goal completion. Feasibility (session completion rates) and acceptability (participant ratings of intervention ease and utility) were assessed via descriptive statistics, and pre-post improvements in psychological, functional, and physical activity outcomes at 12 weeks were examined via mixed effects regression models. Results: Twelve midlife adults with low baseline physical activity enrolled in the single-arm trial. Overall, 76.8% of all possible sessions were completed by participants, and mean ratings of weekly phone sessions were 8.9/10 (SD 1.6), exceeding our a priori thresholds for feasibility and acceptability. Participants demonstrated generally medium to large effect size magnitude improvements in accelerometer-measured physical activity, psychological outcomes, and function. Conclusions: A novel, midlife-specific phone- and text-based PP-MI intervention was feasible and had promising effects on physical activity and other clinically relevant outcomes, supporting next-step testing of this program via a randomized controlled trial.