title: Acute Low-Volume High-Intensity Interval Exercise and Continuous Moderate-Intensity Exercise Elicit a Similar Improvement in 24-h Glycemic Control in Overweight and Obese Adults.
abstract: Background:Acute exercise reduces postprandial oxidative stress and glycemia; however, the effects of exercise intensity are unclear. We investigated the effect of acute low-volume high-intensity interval-exercise (LV-HIIE) and continuous moderate-intensity exercise (CMIE) on glycemic control and oxidative stress in overweight and obese, inactive adults.Methods:Twenty-seven adults were randomly allocated to perform a single session of LV-HIIE (9 females, 5 males; age: 30 ± 1 years; BMI: 29 ± 1 kg·m-2; mean ± SEM) or CMIE (8 females, 5 males; age: 30 ± 2.0; BMI: 30 ± 2.0) 1 h after consumption of a standard breakfast. Plasma redox status, glucose and insulin were measured. Continuous glucose monitoring (CGM) was conducted during the 24-h period before (rest day) and after exercise (exercise day).Results:Plasma thiobarbituric acid reactive substances (TBARS; 29 ±13%,p< 0.01; mean percent change ±90% confidence limit), hydrogen peroxide (44 ± 16%,p< 0.01), catalase activity (50 ± 16%,p< 0.01), and superoxide dismutase activity (21 ± 6%,p< 0.01) significantly increased 1 h after breakfast (prior to exercise) compared to baseline. Exercise significantly decreased postprandial glycaemia in whole blood (-6 ± 5%,p< 0.01), irrespective of the exercise protocol. Only CMIE significantly decreased postprandial TBARS (CMIE: -33 ± 8%,p< 0.01; LV-HIIE: 11 ± 22%,p= 0.34) and hydrogen peroxide (CMIE: -25 ± 15%,p= 0.04; LV-HIIE: 7 ± 26%;p= 0.37). Acute exercise provided a similar significant improvement in 24-h average glucose levels (-5 ± 2%,p< 0.01), hyperglycemic excursions (-37 ± 60%,p< 0.01), peak glucose concentrations (-8 ± 4%,p< 0.01), and the 2-h postprandial glucose response to dinner (-9 ± 4%,p< 0.01), irrespective of the exercise protocol.Conclusion:Despite elevated postprandial oxidative stress compared to CMIE, LV-HIIE is an equally effective exercise mode for improving 24-h glycemic control in overweight and obese adults.
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University Melbourne, VIC, Australia.
authors.forename: Lewan
authors.initials: L
authors.lastname: Parker
authors.affiliation: Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University Geelong, VIC, Australia.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Shaw
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University Melbourne, VIC, Australia.
authors.forename: Lauren
authors.initials: L
authors.lastname: Banting
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria University Melbourne, VIC, Australia.
authors.forename: Itamar
authors.initials: I
authors.lastname: Levinger
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Health and Biomedicine, Victoria University Melbourne, VIC, Australia.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Hill
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Health and Biomedicine, Victoria University Melbourne, VIC, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: McAinch
authors.affiliation: Clinical Exercise Science Research Program, Institute of Sport, Exercise and Active Living, College of Sport and Exercise Science, Victoria UniversityMelbourne, VIC, Australia; Monash Centre for Health Research and Implementation, School of Public Health and Preventative Medicine, Monash University Clayton VictoriaMelbourne, VIC, Australia.
authors.forename: Nigel K
authors.initials: NK
authors.lastname: Stepto
keywords: HIIT; PCOS; continuous glucose monitoring; oxidative stress; postprandial; redox