261996 Examining the Immediate Effects of Intention and Self-Efficacy on Physical Activity among Adults: An Ecological Momentary Assessment Study

Tuesday, October 30, 2012

Yue Liao, MPH , Institute for Health Promotion and Disease Prevention Research, University of Southern California, Los Angeles, CA
Jimi Huh, PhD , Institute for Health Promotion and Disease Prevention Research, University of Southern California, Los Angeles, CA
Donna Spruijt-Metz, PhD , Institute for Health Promotion and Disease Prevention Research, University of Southern California, Los Angeles, CA
Stephen Intille, PhD , Department of Health Science, Northeastern University, Boston, MA
Mary Ann Pentz, PhD , Institute for Health Promotion and Disease Prevention Research, University of Southern California, Los Angeles, CA
Genevieve Dunton, PhD , Institute for Health Promotion and Disease Prevention Research, University of Southern California, Los Angeles, CA
Introduction: Intention and self-efficacy (SE) are recognized as important cognitive determinants for physical activity (PA). However, few studies have examined the near-time (within a few hours) effects of intention and SE on PA. Methods: This study used electronic surveys delivered by mobile phones to assess adults' intention and SE in PA during the course of their everyday life. PA was measured by an accelerometer (Actigraph GT2M) which participants (N=58, ages 27-73, 74% female, and 55% overweight/obese) worn on a belt at the right hip. Participants were monitored for 4 days (Sat. Tue.). Questions about intention (I plan to do PA) and SE (I can do PA even if feel tired) within the next few hours were asked up to 4 times a day at random intervals. Total minutes in moderate-to-vigorous physical activity (MVPA) were calculated within the 2 hours after the intention/SE question was answered. Multilevel models controlling for clusters within individuals were fit using prompt-level intention/SE as the predictors, separately, and total MVPA minutes in the next 2 hours as the outcome. All models controlled for age, gender, body mass index, weekend/weekday, and individuals' overall average intention/SE score. Results: Greater intention and SE relative to one's usual (average) level were associated with more total MVPA minutes in the following 2-hour period (p's<.05). Follow-up analyses showed that intention positively predicted subsequent MVPA minutes on weekdays while SE positively predicted MVPA minutes on weekends (p's<.05). Discussion: Future studies could examine what factors influence intention/SE in PA on weekdays versus weekends.

Learning Areas:
Social and behavioral sciences

Learning Objectives:
Examining the immediate effects of intention and self-efficacy on physical activity among adults. Assess adults' intention and self-efficacy in physical activity throughout their average daily life. Monitor adults' physical activity level throughout their average daily life.

Keywords: Physical Activity, Assessments

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been working with projects that promote physical activity using novel technology (i.e., mobile phones, accelerometers) for over 2 years. I have co-authored mutiple journal papers presenting findings from our projects.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.