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 (VO2max) in obese adults. Eighteen participants (35.1 +/- 8.1 (SD) yr; body mass index 36.0 +/- 5.0 kg/m2) were randomized to 8 wk (3 sessions/wk) of either HIIT (10x1min, 90 to 95% maximum heart rate (HRmax), 1-min active recovery) or MICT (30 min, 70 to 75% HRmax). Brachial artery flow-mediated dilation (FMD) increased after HIIT (5.13 +/- 2.80% versus 8.98 +/- 2.86%, p = 0.02) but not after MICT (5.23 +/- 2.82% versus 3.05 +/- 2.76%, p = 0.16). Resting artery diameter increased after MICT (3.68 +/- 0.58 mm versus 3.86 +/- 0.58 mm, p = 0.02) but not after HIIT (4.04 +/- 0.70 mm versus 4.09 +/- 0.70 mm; p = 0.63). There was a significant (p = 0.02) group x time interaction in low flow-mediated constriction (L-FMC) between MICT (0.63 +/- 2.00% versus -2.79 +/- 3.20%; p = 0.03) and HIIT (-1.04 +/- 4.09% versus 1.74 +/- 3.46%; p = 0.29). VO2max increased (p < 0.01) similarly after HIIT (2.19 +/- 0.65 l/min versus 2.64 +/- 0.88 l/min) and MICT (2.24 +/- 0.48 l/min versus 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 about 25% less energy expenditure than MICT.

Full text (sometimes free) may be available at these link(s):      help

• PubMed Central
• DOI
• PubMed
• PDF locator
• publisher