Abstract
Text messages can promote physical activity plan execution (Prestwich, Perugini & Hurling, 2010), but it is unknown if they can promote plan formation. Our study investigated whether text messages could be used to promote the formation of physical activity plans. We determined if 1) text messages about planning increased planning more than text messages about physical activity, 2) if tailored text messages about planning increased planning more than generic text messages about planning, and 3) if planning was maintained over time. Participants were inactive adults (n=239, Mage=30.7±4.8yrs) with access to email and text messaging. Participants received generic messages about physical activity, generic messages about planning or tailored messages about planning. Each week for two months, participants were emailed a tool to plan their physical activity. Whether participants used this tool was assessed at baseline (T0), after one month of receiving text messages (T1) and after an additional month without text messages (T2). There were no differences in planning between groups that received messages about planning or physical activity at T1 or T2, ps>.05. More participants who received tailored text messages about planning made at least one plan by T1 than participants who received generic messages about planning, χ2(1)=3.889, p<.05. This difference did not persist at T2, p>.05. For all groups, planning was maintained from T0 to T1, ps>.05, but decreased from T1 to T2, McNemars χ2(1)>17.455, ps<.001. Generic text messages about physical activity or tailored messages about planning can increase planning, but planning may not be sustained over time.
