The Effects of Breaking Up Prolonged Sitting on Cognitive Performance in Middle‐Aged and Older Adults: Dose Response Analysis of a Randomized Crossover Trial

Abstract

AbstractBackgroundSedentary behavior (SED) is highly prevalent and associated with poor health outcomes and cognitive decline, independent of physical activity (PA). Studies have established the harmful effects on cognition and information processing, and while PA guidelines endorse reducing SED, they fail to address how often SED should be broken up, and for how long. The purpose of this study is to assess how frequently and for how long SED should be disrupted with light‐intensity physical activity (PA) to offset the effects on cognitive performance.MethodA randomized crossover study of n = 11 middle and older aged adults (>45 years) completed five 8‐hour visits: a sedentary (control) condition and four experimental conditions with varied walking (1.9 mph, 0% grade) frequency and durations: every 30 minutes for 1 minute, every 30 minutes for 5 minutes, every 60 minutes for 1 minute, and every 60 minutes for 5 minutes. Cognition was assessed at baseline, 4 hours, and 6 hours via the Single Digit Modalities Test (SDMT), a validated cognitive performance measure that assesses information processing speed and accuracy.ResultCompared with control, there was significant improvement in SDMT score for the every 30 minutes for 5 minutes dose (net difference compared to control: 3.1 [SE: 1.4], p‐value = 0.034), every 60 minutes for 1 minute dose (net difference compared to control: 3.4 [SE: 1.4], p‐value = 0.016), and every 60 minutes for 5 minutes dose (net difference compared to control: 3.3 [SE: 1.4], p‐value = 0.017). The effect on SDMT was not statistically significant for the every 30 minutes for 1 minute dose, but a positive trend was observed (net difference compared to control: 2.6 [SE: 1.4], p‐value = 0.069).ConclusionThere was a significant effect of breaking up SED on SDMT scores with light intensity walking for both low frequency breaks (1 minute every 60 minutes and for 5 minutes every 60 minutes) and high frequency breaks (5 minutes every 60 minutes). This suggests that even brief breaks in SED may offset harmful effects on cognitive performance. This result provides a specific and achievable mechanism for offsetting the harm caused by SED on cognitive performance.