Background: The aim of this randomized, 3-period, 3-treatment crossover trial was to examine the acute effects of regularly breaking up seated office work with short bouts of standing or light-intensity walking on postprandial interstitial glucose concentration.
Methods: Seventeen middle-aged office workers performed 3 5-hour trial conditions at their workplace in a random order: 1) uninterrupted sitting, 2) sitting interrupted by 2 minutes of standing every 20 minutes, and 3) sitting interrupted by 2 minutes of light-intensity walking every 20 minutes. Participants consumed 2 standardized test drinks at the start of each trial condition and an iPro2 continuous glucose monitoring system (CGMS) recorded average interstitial glucose concentration every 5 minutes for the duration of the study.
Results: The 5-hour interstitial glucose incremental area under the curve (iAUC) was 55.5% lower after sitting interrupted by light-intensity walking compared with after uninterrupted sitting (95% CI, -104.2% to -6.8%). There was also a suggestion of a beneficial effect of regular standing breaks, particularly in overweight men, although they were not as effective as the walking breaks (mean difference [95% CI], -29.6% [-73.9% to 14.7%]).
Conclusions: Regularly breaking up prolonged sitting lowers postprandial glycemia in middle-aged adults without metabolic impairment.
Keywords: continuous glucose monitoring; postprandial glucose; prolonged sitting; workplace.