Effects of Uninterrupted and Interrupted Sitting on Central Blood Pressure in Chronic Stroke Patients: A Randomized Crossover Trial

BACKGROUND Sedentary behaviour independently contributes to cardiovascular disease risk. In healthy adults, prolonged uninterrupted sitting acutely elevates blood pressure, whereas light-activity breaks attenuate this response. Whether such strategies confer similar benefits in high-risk populations, such as chronic stroke survivors, remains unanswered. OBJECTIVES To determine whether non-ambulatory, seated heel-raise interruptions every 10 minutes would attenuate central systolic blood pressure (cSBP) during 3 hours of prolonged sitting in individuals with chronic stroke. We hypothesized that the experimental (heel-raise interruption) condition (EXP) would significantly mitigate the cSBP response relative to uninterrupted sitting (CON). METHODS Using a randomized crossover design, 15 chronic stroke patients (X = 69.3; SD = 10.8 y; 10 male) completed two 3-hour conditions: CON and EXP (10 seated bi-lateral heel raises at 1 rep per second every 10 minutes). Central and peripheral blood pressures were assessed pre- and post-each condition using the SphygmoCor XCEL. Condition by Time interactions were tested using repeated-measures ANOVA. RESULTS The primary hypothesis was confirmed: a significant Condition by Time interaction was detected for cSBP (p < 0.05; partial eta squared = 0.28), with EXP eliciting a smaller increase than CON (5.6 mmHg [95% CI;6.4, 17.6] vs. 9.6 mmHg [95%CI; 2.4, 21.6]). CONCLUSIONS Heel-raise interruptions every 10 minutes attenuate the cSBP response to prolonged sitting in chronic stroke patients and reduce cardiac workload. Frequent, non-ambulatory activity breaks represent a practical secondary prevention strategy for this population, though higher intensity or frequency may be required to fully protect vascular function.