title: Targeting specific interstitial glycemic parameters with high-intensity interval exercise and fasted-state exercise in type 2 diabetes.
abstract: OBJECTIVE
  To compare the acute glycemic responses to a bout of high-intensity interval exercise (HIIE) and energy-matched moderate-intensity continuous exercise (MICE) performed under fasted and postprandial conditions.
  
  
  METHODS
  A randomized, controlled, crossover design was used. Ten individuals with type 2 diabetes were each tested in five experimental conditions after an overnight fast: 1) fasted-state HIIE (HIIEfast); 2) post-breakfast HIIE (HIIEfed); 3) fasted-state MICE (MICEfast); 4) post-breakfast MICE (MICEfed); and 5) no exercise (control). MICE was performed at workload corresponding to 55% of V.V̇O2peak, whereas HIIE was composed of repetitions of three minutes at workload corresponding to 40% followed by one minute at workload corresponding to 100% V.V̇̇O2peak. Interstitial glucose was monitored by continuous glucose monitoring over 24h under standardized diet and medication.
  
  
  RESULTS
  Fasted-state exercise attenuated postprandial glycemic increments (p<0.05) to a greater extent than post-breakfast exercise did. HIIE reduced nocturnal and fasting glycemia on the day following exercise more than MICE did (main effect: both p<0.05). Compared to the control condition, HIIEfast lowered most interstitial glycemic parameters, i.e., 24-h mean glucose (-1.5mmol·l(-1); p<0.05), fasting glucose (-1.0mmol·l(-1); p<0.05), overall postprandial glycemic increment (-257mmol·360min·l(-1); p<0.05), glycemic variability (-1.79mmol·l(-1); p<0.05), and time spent in hyperglycemia (-283min; p<0.05).
  
  
  CONCLUSIONS
  This study showed that HIIE is more effective than MICE in lowering nocturnal/fasting glycemia. Exercise performed in the fasted state reduces postprandial glycemic increments to a greater extent than post-breakfast exercise does. Performing HIIE under fasted condition may be most advantageous as it lowered most aspects of glycemia.
authors.affiliation: Faculty of Physical Education & Recreation, University of Alberta, 1-052 Li Ka Shing Center for Health Research Innovation, Physical Activity and Diabetes Laboratory, Edmonton, Alberta, Canada, T6G 2H9.
authors.forename: Tasuku
authors.initials: T
authors.lastname: Terada
authors.affiliation: Department of Medicine, Faculty of Medicine, University of Calgary, Foothills Medical Center-North Tower, 9th Floor 1403-29th Street NW, Calgary, Alberta, Canada, T2N 2T9.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Wilson
authors.affiliation: Faculty of Physical Education & Recreation, University of Alberta, 1-052 Li Ka Shing Center for Health Research Innovation, Physical Activity and Diabetes Laboratory, Edmonton, Alberta, Canada, T6G 2H9.
authors.forename: Etienne
authors.initials: E
authors.lastname: Myette-Côté
authors.affiliation: Faculty of Physical Education & Recreation, University of Alberta, 1-052 Li Ka Shing Center for Health Research Innovation, Physical Activity and Diabetes Laboratory, Edmonton, Alberta, Canada, T6G 2H9.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Kuzik
authors.affiliation: Faculty of Physical Education & Recreation, University of Alberta, 1-052 Li Ka Shing Center for Health Research Innovation, Physical Activity and Diabetes Laboratory, Edmonton, Alberta, Canada, T6G 2H9.
authors.forename: Gordon J
authors.initials: GJ
authors.lastname: Bell
authors.affiliation: Department of Agricultural, Food and Nutritional Science, University of Alberta, 2-012D Li Ka Shing Center for Health Research Innovation, Edmonton, Alberta, Canada, T6G 2H9.
authors.forename: Linda J
authors.initials: LJ
authors.lastname: McCargar
authors.affiliation: Faculty of Physical Education & Recreation, University of Alberta, 1-052 Li Ka Shing Center for Health Research Innovation, Physical Activity and Diabetes Laboratory, Edmonton, Alberta, Canada, T6G 2H9. Electronic address: nboule@ualberta.ca.
authors.forename: Normand G
authors.initials: NG
authors.lastname: Boulé
mesh_terms: D000368:Aged; D000416:Alberta; D062408:Breakfast; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000628:therapy*; D004734:Energy Metabolism; D045604:Extracellular Fluid / Q000378:metabolism; D005215:Fasting; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000209:etiology / Q000517:prevention & control*; D007003:Hypoglycemia / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009043:Motor Activity; D010101:Oxygen Consumption; D005082:Physical Exertion; D019518:Postprandial Period
chemical_list: D005947:Glucose
keywords: Continuous glucose monitoring; Fasted-state exercise; Glycemic variability; High-intensity interval exercise; Postprandial glucose concentration