‘Exercise snacks’ before meals: a novel strategy to improve glycaemic control in individuals with insulin resistance

• Published in: Diabetologia Vol. 57; no. 7; pp. 1437 - 1445
• Main Authors: Francois, Monique E., Baldi, James C., Manning, Patrick J., Lucas, Samuel J. E., Hawley, John A., Williams, Michael J. A., Cotter, James D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2014; Springer; Springer Nature B.V
• Subjects: Adult; Biological and medical sciences; Blood Glucose - metabolism; Cross-Over Studies; Diabetes; Diabetes Mellitus, Type 2 - blood; Diabetes Mellitus, Type 2 - metabolism; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Exercise; Exercise - physiology; Female; Glucose monitoring; Heart rate; Human Physiology; Humans; Insulin - blood; Insulin resistance; Insulin Resistance - physiology; Internal Medicine; Male; Meals; Meals - physiology; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Nutrition research; Physiology; Snack foods; New Zealand; United Kingdom > UK; Continuous glucose monitoring; Type 2 diabetes; Postprandial glucose; High-intensity interval exercise; Endocrinopathy; Physical exercise; Human; Postprandial; Meal; Metabolic diseases; Glucose; Target tissue resistance; Insulin resistance
• ISSN: 0012-186X; 1432-0428; 1432-0428
• DOI: 10.1007/s00125-014-3244-6

Aims/hypothesis The aim of this study was to investigate whether small doses of intense exercise before each main meal (‘exercise snacks’) would result in better blood glucose control than a single bout of prolonged, continuous, moderate-intensity exercise in individuals with insulin resistance. Methods Nine individuals completed three exercise interventions in randomised order. Measures were recorded across 3 days with exercise performed on the middle day, as either: (1) traditional continuous exercise (CONT), comprising 30 min moderate-intensity (60% of maximal heart rate [HR max ]) incline walking before dinner; (2) exercise snacking (ES), consisting of 6 × 1 min intense (90% HR max ) incline walking intervals 30 min before each meal; or (3) composite exercise snacking (CES), encompassing 6 × 1 min intervals alternating between walking and resistance-based exercise, 30 min before meals. Meal timing and composition were controlled within participants for exercise interventions. Results ES attenuated mean 3 h postprandial glucose concentration following breakfast (by 1.4 ± 1.5 mmol/l, p  = 0.02) but not lunch (0.4 ± 1.0 mmol/l, p  = 0.22), and was more effective than CONT following dinner (0.7 ± 1.5 mmol/l below CONT; p  = 0.04). ES also reduced 24 h mean glucose concentration by 0.7 ± 0.6 mmol/l ( p  = 0.01) and this reduction persisted for the subsequent 24 h (lower by 0.6 ± 0.4 mmol/l vs CONT, relative to their baselines; p  = 0.01). CES was just as effective as ES ( p  > 0.05 for all glycaemic variables) at improving glycaemic control. Conclusions/interpretation Dosing exercise as brief, intense ‘exercise snacks’ before main meals is a time-efficient and effective approach to improve glycaemic control in individuals with insulin resistance.