Delayed Changes in Postprandial Glucose in Response to Light-Walking Breaks from Prolonged Sitting
Year: 2015
Type: conference-abstract
Abstract: Regular breaking-up of prolonged sitting with short activity bouts reduces postprandial glucose concentrations. However, the time required for breaks to lower postprandial glucose is unknown. PURPOSE: To examine the impact, compared to uninterrupted sitting, of frequent walking breaks on the timing of postprandial glucose changes. METHODS: In a cross-over design, 19 inactive overweight/obese adults completed 2 experimental conditions separated by one week. They entered the laboratory in a fasted state, sat for 2 hours and then consumed a liquid meal (75g carbohydrate, 50g fat). They then either remained seated for an additional 5 hours (SED) or performed regular light walking breaks from sitting (3 minutes at 3.2 km/h) every 30 minutes, beginning 30 minutes after the meal (BR). Interstitial glucose was measured using a Medtronic iPro2 continuous glucose monitor every 5 minutes. Three hour postprandial glucose area under the curve (PPG AUC; trapezoidal method) was calculated and glucose concentrations determined at 60 minute intervals up to 4 hours post-meal. T-tests and mixed model linear regressions examined differences between conditions and time by condition interactions. Data are presented as mean ± SEM. RESULTS: There were no differences in 3-hour PPG AUC between conditions (SED: 22.02±1.24, PA: 21.95±1.12 (mmol/L)*hr). Mean glucose was highest between 1-2 hours post-meal for both conditions (SED: 8.32±0.58, BR: 8.21±0.61 mmol/L). Compared to the immediate post-meal glucose (0-1 hours), 2-3 hours post-meal glucose for the BR condition was significantly lower (6.45±0.41 mmol/L) while glucose in SED remained elevated (7.17±0.47 mmol/L, p=0.01). The effect of the BR condition was maintained through 4 hours post meal. CONCLUSIONS: The glucose-lowering effect of light walking breaks from sitting is not evident until least 90 minutes after the first break. Future studies should include examination of whether an accumulation of activity that is required to achieve the glucose lowering effect of physical activity. This study was funded by a UMass Amherst SPHHS international travel grant and the Swedish Research Council for Health, Working Life and Welfare.
Language: English
Topic: Physical Activity and Health
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2474884234