Effect of 2 weeks of sprint interval training on health-related outcomes in sedentary overweight/obese men

The aim of this study was to investigate the effects of very high intensity sprint interval training (SIT) on metabolic and vascular risk factors in overweight/obese sedentary men. Ten men (age, 32.1 +/- 8.7 years; body mass index, 31.0 +/- 3.7 kg m(-2)) participated. After baseline metabolic, anthropometric, and fitness measurements, participants completed a 2-week SIT intervention, comprising 6 sessions of 4 to 6 repeats of 30-second Wingate anaerobic sprints on an electromagnetically braked cycle ergometer, with 4.5-minute recovery between each repetition. Metabolic, anthropometric, and fitness assessments were repeated post-intervention. Both maximal oxygen uptake (2.98 +/- 0.15 vs 3.23 +/- 0.14 L min(-1), P = .013) and mean Wingate power (579 +/- 24 vs 600 +/- 19 W, P = .040) significantly increased after 2 weeks of SIT. Insulin sensitivity index (5.35 +/- 0.72 vs 4.34 +/- 0.72, P = .027) and resting fat oxidation rate in the fasted state (0.13 +/- 0.01 vs 0.11 0.01 g min(-1), P = .019) were significantly higher and systolic blood pressure (121 3 vs 127 3 mm Hg, P = .020) and resting carbohydrate oxidation in the fasted state (0.03 0.01 vs 0.08 +/- 0.02 g min(-1), P = .037) were significantly lower 24 hours post-intervention compared with baseline, but these changes were no longer significant 72 hours post-intervention. Significant decreases in waist (98.9 +/- 3.1 vs 101.3 +/- 2.7 cm, P = .004) and hip (109.8 +/- 2.2 vs 110.9 +/- 2.2 cm, P = .017) circumferences compared with baseline were also observed after the intervention. Thus, 2 weeks of SIT substantially improved a number of metabolic and vascular risk factors in overweight/obese sedentary men, highlighting the potential for this to provide an alternative exercise model for the improvement of vascular and metabolic health in this population. (C) 2010 Elsevier Inc. All rights reserved.