The Effects of Prolonged Sitting on Cerebral Perfusion and Executive Function

The study purpose was to determine if prolonged (3-hr) sitting impaired (a) cerebral perfusion and executive function, (b) systemic vascular function, and (c) if heel raise exercises prevent impairments. Subjects (n=20) participated in a control (CON) and experimental heel-raise (HEEL) study. Near Infra-red Spectroscopy was used to measure cerebral perfusion and venous pooling in the legs. A Stroop Task was used to assess executive function. Vascular health was measured using pulse wave velocity and pulse wave analysis. Cerebral perfusion and Stroop was not significantly changed.However, venous pooling did occur in the legs (p<0.05) and systemic vascular health was negatively affected (p<0.05) in both days. Prolonged sitting may not acutely affect cerebral perfusion or executive function in young, healthy individual like it negatively effects vascular health. The link between vascular interruption and brain function during prolonged sitting is unclear and future research should address alternate assessments of cerebral autoregulation and additional measures of cognition be examined.Master of Art

Effects of acute prolonged sitting on cerebral perfusion and executive function in young adults: a randomized cross-over trial

Exposure to acute prolonged sitting reportedly leads to decreased cerebral blood flow. However, it is unclear whether this exposure translates to decreased cerebral perfusion and executive function, or whether simple strategies to break-up sitting can maintain cerebral perfusion and executive function. This study sought to answer two questions: in young, healthy adults (i) does prolonged (3 h) sitting lead to decreased cerebral perfusion and executive function? and (ii) does breaking-up prolonged sitting, using intermittent calf raise exercises, prevent changes in cerebral perfusion and executive function? Twenty young, healthy participants (21.7 [2.5] y, 70% F, 25.5 [6.1] kg/m2) were randomized to: 3 h sitting with 10 calf raises every 10 min (CALF), and 3 h sitting without calf intermittent calf raises (CON). Prefrontal cortex perfusion was assessed using near-infrared spectroscopy to monitor total hemoglobin (tHB) concentration and tissue saturation index (TSI, oxygenated hemoglobin). Executive function was assessed using the Stroop Word and Color Tasks. Following 3 h sitting, tHb was significantly lower in CALF vs. CON (-2.1 μM, 95% CI: -3.1, -1.1). TSI was not significantly different between conditions (P = .667). Word (1.6 ms, 95% CI: 0.7, 2.5) and Color (1.3 ms, 95% CI: -0.2, 2.8) completion times were longer (worse) for CALF compared to CON. In conclusion, calf raises decreased both cerebral perfusion and executive function. Simple strategies, such as fidgeting or calf raises, which have been reported to preserve vascular function in the legs, appear not to be sufficient enough to benefit cerebral perfusion or executive function