Targeting specific interstitial glycemic parameters with high-intensity interval exercise and fasted-state exercise in type 2 diabetes.
AIMS
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).


CONCLUSION
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.
['Terada|Tasuku|T|', 'Wilson|Ben J|BJ|', 'Myette-Côté|Etienne|E|', 'Kuzik|Nicholas|N|', 'Bell|Gordon J|GJ|', 'McCargar|Linda J|LJ|', 'Boulé|Normand G|NG|']
D000368:Aged D000416:Alberta D062408:Breakfast D018592:Cross-Over Studies D003924:Diabetes Mellitus, Type 2 D004734:Energy Metabolism D045604:Extracellular Fluid D005215:Fasting D005260:Female D005947:Glucose D006801:Humans D006943:Hyperglycemia D007003:Hypoglycemia D008297:Male D008875:Middle Aged D018670:Monitoring, Ambulatory D009043:Motor Activity D010101:Oxygen Consumption D005082:Physical Exertion D019518:Postprandial Period
High-intensity interval exercise Fasted-state exercise Continuous glucose monitoring Glycemic variability Postprandial glucose concentration