Reducing prolonged sedentary time using a treadmill desk acutely improves cardiometabolic risk markers in male and female adults

This study evaluated the acute effects of interrupting prolonged sitting with an accumulated 2h of light-intensity walking on postprandial cardiometabolic risk markers. In this randomised crossover trial, 24 participants (twelve males) aged 18-55years took part in two, 6.5h conditions: 1) prolonged sitting (SIT) and 2) sitting interrupted hourly with 20min light-intensity treadmill desk walking at between 1.2-3.5km/h(-1) (INT-SIT). Standardized meals were provided at 0h and 3h. Blood samples and blood pressure measures were taken hourly. Statistical analyses were completed using linear mixed models. Postprandial incremental area under the curve responses (mmol/L.6.5h) for glucose (4.52 [3.47, 5.56] and 6.66 [5.62, 7.71] for INT-SIT and SIT, respectively) and triglycerides (1.96 [0.96, 2.96] and 2.71 [1.70, 3.71] for INT-SIT and SIT, respectively) were significantly lower in INT-SIT than SIT. Mean systolic and diastolic blood pressure responses were lower by 3% and 4%, respectively, in INT-SIT than SIT (P<0.05). There was no significant condition x sex interaction effect for any outcomes (P>0.05). These findings suggest that interrupting sitting with an accumulated 2h of light-intensity walking acutely improves cardiometabolic risk levels in males and females compared with prolonged sitting.