High-intensity interval walking in combination with acute green tea extract supplementation reduces postprandial blood glucose concentrations in physically inactive participants

Background: Exercise and green tea supplementation have been shown to have the potential to improve postprandial blood glucose concentrations, but past interventions have not often investigated attainable and time effective exercise protocols. Aim: The purpose of this study was to investigate the effects of interval walking exercise and acute green tea extract supplementation on the glycaemic response to an oral glucose tolerance test (OGTT). Method: Twelve physically inactive participants (nine male, three female, age: 22 ± 1 years; body mass: 81.2 ± 16.3 kg; stature: 175.7 ± 9.6 cm; body mass index (in kg/m2): 26.2 ± 4.3) underwent a 2-h OGTT immediately following i) no intervention (REST), ii) placebo and exercise (EX-PLAC), iii) green tea extract supplementation and exercise (EX-GTE), in a random order. The walking exercise consisted of 6 × 1 min of brisk walking (7.92 ± 0.56 km/h) separated by 1 min of slower walking (4.8 km/h). Differences between groups were identified using magnitude-based inferences. Results: The EX-GTE intervention resulted in a ∼9% most likely beneficial effect on blood glucose area under the curve response to the OGTT (702.18 ± 76.90 mmol/L–1·120 min–1) compared with REST (775.30 ± 86.76 mmol/L–1·120 min–1), and a very likely beneficial effect compared with the EX-PLAC (772.04 ± 81.53 mmol/L–1·120 min–1). Conclusion: These data suggest that an EX-GTE intervention can reduce postprandial glucose concentrations in physically inactive individuals.