Physical activity is regulated by controlled processes, such as intentions, and automatic processes, such as habits. Intentions relate to physical activity more strongly for people with weak habits than for people with strong habits, but people’s intentions vary day by day. Physical activity may be regulated by habits unless daily physical activity intentions are strong. University students (N = 128) self-reported their physical activity habit strength and subsequently self-reported daily physical activity intentions and wore an accelerometer for 14 days. On days when people had intentions that were weaker than typical for them, habit strength was positively related to physical activity, but on days when people had typical or stronger intentions than was typical for them, habit strength was unrelated to daily physical activity. Efforts to promote physical activity may need to account for habits and the dynamics of intentions.
Amanda L. Rebar is now with the School of Human, Health, and Social Sciences, Central Queensland University, Rockhampton, QLD, Australia. Steriani Elavsky and Jaclyn P. Maher are with the Department of Kinesiology, Pennsylvania State University, University Park, PA. Shawna E. Doerksen is with the Department of Recreation, Park, and Tourism Management, Pennsylvania State University, University Park, PA. David E. Conroy is with the Departments of Kinesiology and Human Development & Family Studies, Pennsylvania State University, University Park, PA.