title: Effects of high-intensity interval training and moderate-intensity continuous training on endothelial function and cardiometabolic risk markers in obese adults.
abstract: We hypothesized that high-intensity interval training (HIIT) would be more effective than moderate-intensity continuous training (MICT) at improving endothelial function and maximum oxygen uptake (V̇o2 max) in obese adults. Eighteen participants [35.1 ± 8.1 (SD) yr; body mass index = 36.0 ± 5.0 kg/m(2)] were randomized to 8 wk (3 sessions/wk) of either HIIT [10 × 1 min, 90-95% maximum heart rate (HRmax), 1-min active recovery] or MICT (30 min, 70-75% HRmax). Brachial artery flow-mediated dilation (FMD) increased after HIIT (5.13 ± 2.80% vs. 8.98 ± 2.86%, P = 0.02) but not after MICT (5.23 ± 2.82% vs. 3.05 ± 2.76%, P = 0.16). Resting artery diameter increased after MICT (3.68 ± 0.58 mm vs. 3.86 ± 0.58 mm, P = 0.02) but not after HIIT (4.04 ± 0.70 mm vs. 4.09 ± 0.70 mm; P = 0.63). There was a significant (P = 0.02) group × time interaction in low flow-mediated constriction (L-FMC) between MICT (0.63 ± 2.00% vs. -2.79 ± 3.20%; P = 0.03) and HIIT (-1.04 ± 4.09% vs. 1.74 ± 3.46%; P = 0.29). V̇o2 max increased (P < 0.01) similarly after HIIT (2.19 ± 0.65 l/min vs. 2.64 ± 0.88 l/min) and MICT (2.24 ± 0.48 l/min vs. 2.55 ± 0.61 l/min). Biomarkers of cardiovascular risk and endothelial function were unchanged. HIIT and MICT produced different vascular adaptations in obese adults, with HIIT improving FMD and MICT increasing resting artery diameter and enhancing L-FMC. HIIT required 27.5% less total exercise time and ∼25% less energy expenditure than MICT.
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Sawyer
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona.
authors.forename: Wesley J
authors.initials: WJ
authors.lastname: Tucker
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona.
authors.forename: Dharini M
authors.initials: DM
authors.lastname: Bhammar
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona.
authors.forename: Justin R
authors.initials: JR
authors.lastname: Ryder
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona.
authors.forename: Karen L
authors.initials: KL
authors.lastname: Sweazea
authors.affiliation: Arizona State University, School of Nutrition and Health Promotion, Phoenix, Arizona glenn.gaesser@asu.edu.
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Gaesser
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology*; D004727:Endothelium / Q000503:physiopathology*; D004734:Energy Metabolism / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D000072696:High-Intensity Interval Training / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000502:physiology; D012307:Risk Factors; D055815:Young Adult
keywords: cardiovascular; exercise; fitness; flow-mediated dilation; obesity