title: 'Exercise snacks' before meals: a novel strategy to improve glycaemic control in individuals with insulin resistance.
abstract: OBJECTIVE
  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 [HRmax]) incline walking before dinner; (2) exercise snacking (ES), consisting of 6 × 1 min intense (90% HRmax) 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
  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.
authors.affiliation: School of Physical Education, Sport and Exercise Sciences, University of Otago, 46 Union St West, PO Box 56, Dunedin, 9076, New Zealand.
authors.forename: Monique E
authors.initials: ME
authors.lastname: Francois
authors.forename: James C
authors.initials: JC
authors.lastname: Baldi
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Manning
authors.forename: Samuel J E
authors.initials: SJ
authors.lastname: Lucas
authors.forename: John A
authors.initials: JA
authors.lastname: Hawley
authors.forename: Michael J A
authors.initials: MJ
authors.lastname: Williams
authors.forename: James D
authors.initials: JD
authors.lastname: Cotter
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D062407:Meals / Q000502:physiology*; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D007328:Insulin