Comparison of the acute effects of breaking up prolonged sitting time with single-task or a dual-task walking on cognitive function and cerebral blood flow in older adults: a randomized crossover trial.

This randomized cross-over study examined the acute effects of single-task or dual-task walking physical activity (PA) breaks of prolonged sitting among healthy older adults on cognitive performance and cerebral blood flow velocity (CBFv). Twenty-seven healthy older adults (69.4 ± 5.6 years, 25 female) were randomly assigned to engage in three experimental conditions (i.e., control, single-task, and dual-task walking), each one on a different day. All conditions included 3 h of sitting time, with a break every 30 min involving either 2 min of single-task or dual-task walking in the intervention conditions. In the control condition, the participants remained seated for 3 h without any breaks. Cognitive functioning (Trail Making Tests [TMT] A and B, Stroop test, and verbal fluency test) and CBFv were assessed before and 10 min after the cessation of the conditions, and their changes were analyzed with a Generalized Estimated Equation (GEE) model. A significant interaction effect was observed in Verbal Fluency phonological and semantic, and TMA (p < 0.01). It was found an effect size of 0.63 and 0.79 in phonological conditions for dual-task and single-task breaks, respectively. In addition, an effect size of 0.67 and 0.71 in semantic condition for dual-task and walking breaks, respectively, and for the TMA, it was found an effect size of - 0.22 for both break types. Furthermore, a significant improvement in CBFv was observed in the dual-task condition (ES = 0.91) and walking condition (ES = 0.55) (p < 0.05) compared to uninterrupted sitting. PA breaks of prolonged sitting by two different types of breaks are effective in improving verbal fluency and set-shifting performance and increasing the CBFv in older adults.