The effect of frequency of activity interruptions in prolonged sitting on postprandial glucose metabolism: A randomized crossover trial

The primary objective was to test the hypothesis that increased frequency of interruptions in prolonged sitting reduces postprandial glycemia independent of energy intake and expenditure.Healthy, sedentary, centrally obese men (n = 14; age*, 28.2 (23.4; 38.3) years; BMI, 31.9 ± 6.7 kg/m2; VO2max*, 39.5 (38.8; 40.9) ml/min/kg; HbA1c, 5.3 ± 0.4% (34.1 ± 4.2 mmol/mol); mean ± SD (*median (25th; 75th percentile)) completed four 8-h interventions in randomized order: 1) uninterrupted sitting (SIT), 2) sitting interrupted by 2 min of walking (~30% of VO2max) every 20th minute (INT20), 3) sitting interrupted by 6 min of walking every hour (INT60), and 4) sitting interrupted by 12 min of walking every second hour (INT120). A standardized test drink was served at the beginning of and 4 h into the intervention (total of 2310 ± 247 kcal; 50% energy from carbohydrate, 50% energy from fat). Outcomes included the difference in the 8-h total area under the curve (tAUC) for primarily plasma glucose, and secondarily plasma insulin and C-peptide during INT20, INT60, and INT120 compared to SIT.No difference [95% CI] was observed in the primary outcome, the 8-h tAUC for the plasma glucose, during INT20, INT60, and INT120 compared to SIT (-65.3 mmol/l∗min [-256.3; 125.7], +53.8 mmol/l∗min [-143.1; 250.8], and +18.6 mmol/l∗min [-172.4; 209.6], respectively).Interrupting sitting with increasing frequency did not reduce the postprandial plasma glucose response to prolonged sitting in healthy, sedentary, centrally obese men.