Investigation of Web-Based Motivational Interviewing to Increase Physical Activity Participation Among Adults

Abstract

Interventions to enhance physical activity (PA) participation are needed given the high prevalence of under-activity and inactivity (CDC, 2001) and related occurrence of negative health consequences among the general adult population (Kung, Hoyert, Xu, & Murphy, 2008). Preliminary support for a therapeutic technique called Motivational Interviewing (MI) suggests promise for application to enhance PA participation (Burke, Arkowitz, & Menchola, 2003). Given the need for interventions to enhance PA and the preliminary support for MI as an intervention to increase PA, the aims of the current study were to: (a) determine if web-based MI is effective in enhancing PA participation, and (b) assess the mechanisms by which web-based MI enhances PA through changes in targeted cognitive variables. Participants (n= 23, under-active or inactive adults) engaged in four web-based MI sessions. Steps per day, PA, and cognitive variables were assessed across time. Efficacy of MI in enhancing PA participation was demonstrated through: (a) increases in steps per day (t[22]= 2.085, p = 0.049); (b) increases in total PA energy expenditure per week( χ2= 8.430, p = 0.015); and (c) increases in moderate intensity PA energy expenditure per week ( χ2= 13.853, p = 0.001). Although mediation of change in PA by cognitive variables was inconclusive due to sample size, changes were observed in the expected direction for cognitive variables including: (a) percentage of participants classified as action or maintenance stages of change (pre = 25.00%, post1= 70.81%, post2 = 68.18%); (b) decisional balance pros (F[2,42] = 16.192, p