The Effects of Interrupting Prolonged Sitting With Frequent Bouts of Light-Intensity Standing Exercises on Blood Pressure in Stroke Survivors: A Dose Escalation Trial

Abstract

Background: Interrupting prolonged sitting acutely lowers blood pressure in nonstroke populations. However, the dose–response effect in stroke survivors is unknown. The authors investigated different doses of light-intensity standing exercises that interrupt prolonged sitting and reduce blood pressure immediately and over 24 hours in stroke survivors. Methods: Within-participant, laboratory-based, dose escalation trial. Conditions (8 h) were prolonged sitting and 2 experimental conditions of standing exercises with increasing frequency (3 cohorts, 2 × 5 min to 6 × 5 min). The primary outcome is the mean systolic blood pressure. Results: Twenty-nine stroke survivors (aged 66 [12] y) participated. Frequent bouts of standing exercises lowered the mean systolic blood pressure following the 4 × 5-minute (−2.1 mm Hg; 95% confidence interval [CI], −3.6 to −0.6) and 6 × 5-minute conditions (−2.3 mm Hg; 95% CI, −4.2 to −0.5) compared with prolonged sitting. Diastolic blood pressure was lowered following the 6 × 5-minute condition (−1.4 mm Hg; 95% CI, −2.7 to −0.2). The 24-hour systolic blood pressure increased following the 2 × 5-minute condition (6.9 mm Hg; 95% CI, 3.1 to 10.6). Conclusions: Interrupting prolonged sitting with more frequent bouts of standing exercises lowers systolic and diastolic blood pressure in stroke survivors. However, reductions may only be short term, and investigations on sustained effects are warranted.