Purpose: To examine whether reductions in sitting time through alternating 30 minute bouts of sitting and standing can reduce postprandial glucose, insulin and triglyceride responses.
Methods: Twenty-three overweight/obese sedentary office workers (17 males; 6 females; mean +/- SD; age: 48.2 +/- 7.9 yrs, BMI: 29.6 +/- 4.0 kg/m2) undertook two, short-term (5-day) experimental conditions in an equal, randomised (1:1) order. In a simulated office environment, participants performed typical occupational tasks for 8 hours/day while in a: 1) seated work posture (control condition); or, 2) interchanging between a seated and standing work posture every 30 minutes using an electric, height-adjustable workstation (intervention condition). Fasting and postprandial blood samples after a mixed test drink were collected hourly for 4 hours on Day 1 and 5 of each condition to assess serum insulin, plasma glucose and triglycerides. Dietary intake (KJ/d) and physical activity were standardised during each condition. The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12611000632998).
Results: Following adjustment for time (Day 1 and Day5), incremental area under the analyte time curve (iAUC) differed significantly between conditions for plasma glucose (P=0.007) but not for serum insulin or plasma triglycerides. Adjusted mean glucose iAUC was lowered by 11.1% after the intervention condition (6.38mmol/L[middle dot]h [CI: 5.04, 7.71] ) relative to the control condition (7.18mmol/L[middle dot]h [CI: 5.85, 8.52] ). No temporal changes (Day 1 vs Day 5) between conditions were observed.
Conclusion: Alternating standing and sitting in 30 minute bouts results in modest beneficial effects on postprandial glucose responses in overweight/obese office workers.
(C) 2014 American College of Sports Medicine