MobileMums: A Randomized Controlled Trial of an SMS-Based Physical Activity Intervention

Postnatal women (< 12 months postpartum) are at increased risk of physical inactivity. To evaluate the efficacy and feasibility of a theory-based physical activity (PA) intervention delivered to postnatal women primarily via mobile telephone short message service (SMS). Eighty-eight women were randomized to the intervention (n = 45) or minimal contact control (n = 43) condition. The 12-week intervention consisted of a face-to-face PA goal-setting consultation, a goal-setting magnet, three to five personally tailored SMS/week and a nominated support person who received two SMS per week. SMS content targeted constructs of social cognitive theory. Frequency (days/week) and duration (min/week) of PA participation and walking for exercise were assessed via self-report at baseline, 6 and 13 weeks. Intervention participants increased PA frequency by 1.82 days/week (SE +/- 0.18) by 13 weeks (F ((2,85)) = 4.46, p = 0.038) and walking for exercise frequency by 1.08 days/week (SE +/- 0.24) by 13 weeks (F ((2,85)) = 5.38, p = 0.02). Positive trends were observed for duration (min/week) of PA and walking for exercise. Intervention exposure resulted in increased frequency of PA and walking for exercise in postnatal women.