Breaking up prolonged sitting reduces resting blood pressure in overweight/obese adults

Abstract Aim: To compare the effect of 7 h of prolonged sitting on resting blood pressure with asimilar duration of sitting combined with intermittent brief bouts of light-intensity or moderate-intensity physical activity. Methods and results: Overweight/obeseadults(nZ19;aged45 e65years) were recruited for a randomized three-treatment crossover trial with a one-week washout between treatments: 1) uninterrupted sitting; 2) sitting with 2 min bouts of light-intensity walking at 3.2 km/h every 20 min;and, 3) sitting with 2 min bouts of moderate-intensity walking at between 5.8 and 6.4 km/h every 20 min. After an initial 2 h period seated, participants consumed a test meal (75 g carbohydrate,50 g fat) and completed each condition over the next 5 h. Resting blood pressure was assessed oscillometrically every hour as a single measurement, 5 min prior to each activity bout. GEE models were adjusted for sex, age, BMI, fasting blood pressure and treatment order. After adjustment for potential confounding variables, breaking up prolonged sitting with lightand moderate-intensity activity breaks was associated with lower systolic blood pressure [light:120 1 mmHg (estimated marginal mean SEM), P Z 0.002; moderate: 121 1 mmHg, P Z 0.02], compared to uninterrupted sitting (123 1 mmHg). Diastolic blood pressure was also signi fi cantly lower during both of the activity conditions (light: 76 1 mmHg, P Z 0.006; moder- ate: 77 1mmHg, P Z 0.03) compared to uninterrupted sitting (79 1 mmHg). No significant between-condition differences were observed in mean arterial pressure or heart rate. Conclusion: Regularly breaking up prolonged sitting may reduce systolic and diastolic blood pressure.