Long-Term and Acute Benefits of Reduced Sitting on Vascular Flow and Function

PURPOSE: Sedentary behavior increases the risk for cardiovascular and cerebrovascular disease. To understand potential benefits and underlying mechanisms, we examined the acute and long-term impact of reduced sitting-intervention on vascular and cerebrovascular function. METHODS: This prospective study included 24 individuals with increased cardiovascular risk (65±5 years, 29.8±3.9 kg/m). Before and after 16-week reduced sitting, using a mobile-Health device with vibrotactile feedback, we examined: i. vascular function (flow-mediated dilation (FMD)), ii. cerebral blood flow (CBFv, transcranial Doppler), and iii. cerebrovascular function (cerebral autoregulation (CA) and cerebral vasomotor reactivity (CVMR)). To better understand potential underlying mechanisms, before and after intervention, we evaluated the effects of 3-hour sitting with and without light-intensity physical activity breaks (every 30-minutes). RESULTS: The first wave of participants showed no change in sedentary time (n=9, 10.3±0.5 to 10.2±0.5 hours/day, P=0.87). Upon intervention optimization by participants' feedback, the subsequent participants (n=15) decreased sedentary time (10.2±0.4 to 9.2±0.3 hours/day, P0.20). CONCLUSION: Long-term reduction in sedentary behavior improves peripheral vascular function and cerebral blood flow, and acutely prevents impaired vascular function and decreased cerebral blood flow. These results highlight the potential benefits of reducing sedentary behavior to acutely and chronically improve cardio-/cerebrovascular risk