Social-cognitive theories, such as the theory of planned behavior, posit intentions as proximal influences on physical activity (PA). This paper extends those theories by examining within-person variation in intentions and moderate-to-vigorous physical activity (MVPA) as a function of the unfolding constraints in people’s daily lives (e.g., perceived time availability, fatigue, soreness, weather, overeating). College students (N = 63) completed a 14-day diary study over the Internet that rated daily motivation, contextual constraints, and MVPA. Key findings from multilevel analyses were that (1) between-person differences represented 46% and 33% of the variability in daily MVPA intentions and behavior, respectively; (2) attitudes, injunctive norms, self-efficacy, perceptions of limited time availability, and weekend status predicted daily changes in intention strength; and (3) daily changes in intentions, perceptions of limited time availability, and weekend status predicted day-to-day changes in MVPA. Embedding future motivation and PA research in the context of people’s daily lives will advance understanding of individual PA change processes.
David E. Conroy, Steriani Elavsky, Shawna E. Doerksen and Jaclyn P. Maher
Amanda L. Rebar, Steriani Elavsky, Jaclyn P. Maher, Shawna E. Doerksen and David E. Conroy
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.
David E. Conroy, Steriani Elavsky, Amanda L. Hyde and Shawna E. Doerksen
The intention-behavior gap has proven to be a vexing problem for theorists and practitioners interested in physical activity. Intention stability is one factor which moderates this gap. This study articulated and tested contrasting views of intention stability as (a) a dynamic characteristic of people that influences assessment error (and therefore the predictive power of intentions) and (b) the product of a dynamic process that unfolds within people over time. Using an ecological momentary assessment design, young adults (N = 30) rated weekly physical activity intentions for 10 weeks and wore pedometers for the first 4 weeks of the study. Substantial within-person variability existed in intentions over both 4- and 10-week intervals, and this variability was not a function of time exclusively. Multilevel modeling revealed that overall intention strength (across weeks) and weekly deviations in intention strength interacted to predict weekday (but not weekend) physical activity. These findings indicate that the person and context interact to selectively couple or decouple intentions from daily physical activity.
Amanda L. Hyde, Steriani Elavsky, Shawna E. Doerksen and David E. Conroy
Accumulating research indicates that physical activity is motivated by automatic evaluations of physical activity. Little is known about the stability of automatic evaluations or how their dynamics impact physical activity. We tested the measurement invariance and stability of university students’ (N = 164) automatic evaluations of physical activity. In addition, multiple regression and structural equation models with latent interaction variables were used to investigate how changes in automatic evaluations related to change in self-reported physical activity and differences in the level of directly measured physical activity. It was revealed that automatic evaluations had strict measurement invariance and that automatic evaluations have both stable and unstable components. People whose unfavorable automatic evaluations became more favorable over the week showed a larger increase in self-reported physical activity from the previous week than did people whose automatic evaluations remained unfavorable. These results indicated that the dynamics of automatic evaluations and physical activity can be intertwined.
Jaclyn P. Maher, Shawna E. Doerksen, Steriani Elavsky and David E. Conroy
Recent research revealed that on days when college students engage in more physical activity than is typical for them, they also experience greater satisfaction with life (SWL). That work relied on self-reported physical activity and did not differentiate between low levels of physical activity and sedentary behavior. This study was designed to (1) determine if the association between self-reported physical activity and SWL would exist when physical activity was monitored objectively and (2) examine the between- and within-person associations among physical activity, sedentary behavior, and SWL. During a 14-day ecological momentary assessment study, college students (N = 128) wore an accelerometer to objectively measure physical activity and sedentary behavior, and they self-reported their physical activity, sedentary behavior, and SWL at the end of each day. Physical activity and sedentary behavior had additive, within-person associations with SWL across self-reported and objective-measures of behavior. Strategies to promote daily well-being should encourage college students to incorporate greater amounts of physical activity as well as limit their sedentary behavior.
Paul A. Estabrooks, Elizabeth H. Fox, Shawna E. Doerksen, Michael H. Bradshaw and Abby C. King
The purpose of this study was to determine the feasibility and effectiveness of an on-site physical activity (PA) program offered with congregate meals. Study 1 surveyed meal-site users on their likelihood to participate. Study 2 used meal-site-manager interviews and site visits to determine organizational feasibility. Study 3, a controlled pilot study, randomized meal sites to a 12-week group-based social-cognitive (GBSC) intervention or a standard-care control. Studies 1 and 2 indicated that most meal-site users would participate in an on-site PA program, and meal sites had well-suited physical resources and strong organizational support for this type of program. In Study 3, GBSC participants increased their weekly PA over those in the control condition (p < .05, ES = .79). Results indicated that changes in task cohesion might have mediated intervention effectiveness. These studies demonstrate that a PA program offered in this venue is feasible, is effective in promoting PA, and could have a strong public health impact.