Habit strength moderates the effects of daily action planning prompts on physical activity but not sedentary behavior.

This study was designed to examine the moderating influence of habit strength on daily action planning effects on physical activity and sedentary behavior. A 2 by 2 design was used with experimental factors corresponding to action planning interventions for (a) engaging in physical activity and (b) limiting or interrupting sedentary behavior. At the end of each day for 1 week, university students (n = 195) completed (a) a questionnaire about their behavior during the day and behavioral intentions for the following day and (b) a planning intervention(s) corresponding to their randomly assigned experimental condition. Action planning increased physical activity in those with weak habits but decreased physical activity in those with strong habits compared with those who did not create action plans. Action planning did not impact sedentary behavior. Action planning was a useful behavior change technique for increasing physical activity in people with weak habits, but may be iatrogenic for those with strong habits.

Daily satisfaction with life is regulated by both physical activity and sedentary behavior.

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.