Dual processing approach to sedentary behavior and physical activity in the workplace.

Regular physical activity is an important health promoting behavior. Yet, many adults live sedentary lifestyles, especially during their workday. The current study applies an extended theory of planned behavior model, incorporating affective attitudes and instrumental attitudes, along with habit, to predict limiting sedentary behavior and physical activity within an office environment. Theory of planned behavior constructs and habit were assessed with an online survey on a sample of 180 full-time office workers, with self-reported behavior assessed 1 week later (Mage = 25.97, SDage = 10.24; 44 males, 134 females, and 2 nonbinary). Model fit was indicated by BRMSEA (M = 0.057, SD = 0.023), B γ^ (M = 0.984, SD = 0.010) and BCFI (M = 0.959, SD = 0.026), accounting for 46.1% of variance in intention, 21.6% of variance in sedentary behavior, and 17.4% of variance in physical activity behavior. A Bayesian structural equation model revealed direct effects of instrumental attitudes and perceived behavioral control on intention to limit sedentary behavior, direct effects of intention and perceived behavioral control on limiting sedentary behavior, and direct effects of perceived behavioral control and habit on engaging in physical activity. The current study indicates intentions to be active in the office are primarily driven by beliefs about the benefits of activity and individuals' perceived level of control, rather than normative or affective beliefs. As behavior was predicted by both intention and habit, findings also indicate office-based activity is likely not always a consciously driven decision. These findings may have implications for improving activity levels in this highly sedentary population.