Twenty minutes of passive stretching lowers glucose levels in an at-risk population: an experimental study.

QUESTION Can passive static stretching lower blood glucose in an at-risk population? DESIGN Randomised, within-participant experimental study. PARTICIPANTS 22 adults (17 males) either at increased risk of Type 2 diabetes or with Type 2 diabetes. INTERVENTION The participants reported to the laboratory 2hr after eating a meal, and drank 355ml of fruit juice (∼43g carbohydrate). Thirty minutes later, they underwent either a 40min passive static stretching regimen or a mock passive stretching regimen. Stretching consisted of six lower body and four upper body static passive stretches. For the mock stretches, the same positions were adopted, but no tension was applied to the musculature. OUTCOME MEASURES Blood glucose levels for both the stretching and mock stretching were analysed from a finger prick sample using a hand-held glucometer. Values were obtained at baseline (0min), during the regimen (20min), and after the regimen (40min) on both study days. RESULTS Compared to mock stretch, stretching resulted in a significantly greater drop in blood glucose at 20min (mean difference 28mg/dL, 95% CI 13 to 43; or 1.57mmol/L, 95% CI 0.72 to 2.39). This effect was also statistically significant at 40min (mean difference 24mg/dL, 95% CI 9 to 39; or 1.35mmol/L, 95% CI 0.50 to 2.17). CONCLUSION These results suggest that passive static stretching of the skeletal muscles may be an alternative to exercise to help lower blood glucose levels.