title: High-intensity interval training without weight loss improves exercise but not basal or insulin-induced metabolism in overweight/obese African American women.
abstract: The purpose of this randomized controlled clinical trial was to determine the effect of a 14-week high-intensity interval training (HIIT) intervention with weight stability on metabolic flexibility, insulin sensitivity, and cardiorespiratory fitness in sedentary, premenopausal, nondiabetic, overweight/obese African American women. Twenty-eight subjects were allocated to one of two groups: HIIT, which performed three sessions per week of four high-intensity cycling intervals, or a control group (CON), which maintained their normal level of physical activity. Diet was controlled for all subjects to ensure weight stability. Pre- and postintervention (pre/post), subjects completed an incremental cycling test to limit of tolerance and, following a 10-day high-fat controlled feeding period, a euglycemic-hyperinsulinemic clamp to determine insulin sensitivity and substrate oxidation. Nine members of HIIT (age, 29 ± 4 yr; body mass, 90.1 ± 13.8 kg) and eleven members of CON (age, 30 ± 7 yr; body mass, 85.5 ± 10.7 kg) completed the study. HIIT experienced an increased limit of tolerance (post, 1,124 ± 202 s; pre, 987 ± 146 s; P < 0.05), gas exchange threshold (post, 1.29 ± 0.34 liters/min; pre, 0.97 ± 0.23 liters/min; P < 0.05), and fat oxidation at the same absolute submaximal work rate compared with CON (P < 0.05 for group-by-time interaction in all cases). However, changes in peak oxygen consumption (V̇o2peak), insulin sensitivity, free fatty acid suppression during insulin stimulation, and metabolic flexibility were not different in HIIT compared with CON. High-intensity interval training with weight stability increased exercise fat oxidation and tolerance in subjects at risk for diabetic progression, but did not improve insulin sensitivity or fat oxidation in the postabsorptive or insulin-stimulated state.
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and.
authors.forename: Avigdor D
authors.initials: AD
authors.lastname: Arad
authors.affiliation: Teachers College, Department of Biobehavioral Sciences, Columbia University, New York, New York.
authors.forename: Fred J
authors.initials: FJ
authors.lastname: DiMenna
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and.
authors.forename: Naketa
authors.initials: N
authors.lastname: Thomas
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Tamis-Holland
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and.
authors.forename: Richard
authors.initials: R
authors.lastname: Weil
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and.
authors.forename: Allan
authors.initials: A
authors.lastname: Geliebter
authors.affiliation: The New York Obesity Nutrition Research Center, Mt. Sinai St. Luke's Hospital, New York, New York; and jalbu@chpnet.org.
authors.forename: Jeanine B
authors.initials: JB
authors.lastname: Albu
mesh_terms: D000328:Adult; D001741:Black or African American; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition; D004734:Energy Metabolism; D005081:Exercise Therapy / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000208:ethnology*; D050356:Lipid Metabolism; D009519:New York City / Q000453:epidemiology; D009765:Obesity / Q000097:blood / Q000208:ethnology / Q000503:physiopathology / Q000628:therapy*; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin
keywords: exercise tolerance; high-intensity interval training; insulin sensitivity; metabolic flexibility