Innovation to motivation—pilot study of a mobile phone intervention to increase physical activity among sedentary women

Abstract

Objectives This uncontrolled pilot study assessed changes in pedometer-measured step counts and self-reported physical activity during a 3-week mobile phone-based intervention. We also explored whether age, BMI, and psychosocial factors were associated with changes in step counts. Methods Forty-one sedentary adult women in San Francisco, California were asked to report their pedometer steps using a study-supplied mobile phone from June to September 2008. In the second and third weeks, daily prompts delivered by the mobile phone encouraged participants to increase steps by 20% from the previous week. Results Mean age was 48 years. Average daily total steps increased by approximately 800 or 15% over three weeks ( p < 0.001). Lower BMI, no antidepressant use, and lower self-reported health status were associated with higher step counts at baseline. Improvements in self-reported will-power were associated with increases in step counts ( p < 0.001). Neither age ( p = 0.55) nor BMI ( p = 0.13) was significantly associated with changes in activity over the 3 weeks. Conclusions The intervention appeared to motivate sedentary women to increase their physical activity. A randomized controlled clinical trial is warranted and feasible.