Does planning more bite-sized exercise sessions lead to more bites of brownie? An experimental test of self-control performance


Complex behaviours like physical activity (PA) require considerable cognitive resources, such as planning and deliberation. In line with the strength model of self-control, the cognitive resources needed to engage in planning may also contribute to subsequent failures in self-control. National PA guidelines have suggested that aerobic activity could be broken up into multiple 10-minute bouts accumulated throughout the day as opposed to performing one 30-minute bout. Does the task of planning multiple bouts exert more cognitive resources than planning one longer single bout? This acute study compared the effects of planning three, 10-minute bouts of PA (Multiple Plan [MP]) compared to planning one, 30-minute bout of PA (Single Plan [SP]), on subsequent tasks requiring self-control. Sixty-five low-active university students were randomly assigned to two experimental conditions: SP (planned one 30-minute exercise bout) or MP (planned three 10-minute exercise bouts). Participants then completed the cold pressor task and were given the opportunity to eat a self-selected amount of brownies. Contrary to hypotheses, there were no statistically significant between-group differences in the duration of the cold pressor task between (MSP = 107.97 vs. MMP = 126.56, p = .29) or the amount of the brownies eaten between (MSP = 33.90 vs. MMP = 40.69, p = .37). Our study is the first to examine the potential negative effects of planning multiple versus single bouts of PA on self-control performance. Future experimental research is needed to elucidate whether planning expends enough self-regulatory resources to reduce performance on subsequent tasks requiring self-control.