Acute bout of sprint interval vs. endurance exercise on insulin senstivity

Abstract

An acute bout of endurance exercise (EE; ~45min) enhances insulin sensitivity (IS), whereas less is known regarding an acute bout of repeated sprint interval exercise (SIE). Thus, we tested the hypothesis that an acute bout of five 30sec sprints performed at 125% of VO2peak (SIE) would increase IS similar to EE for 45 minutes at 70% VO2peak. Eight healthy, sedentary, males (18–22yrs; VO2peak 45.2±4.6 ml.kg.min−1; <1.5 d/wk structured exercise; % body fat, 16.5±3.4) underwent three oral glucose tolerance tests (OGTT) following three conditions: no exercise the day before (OGTTN‐EX); SIE the day prior (OGTTSIE); and EE the day prior (OGTTEE). SIE and EE sessions were randomized for each subject. Subjects consumed identical meals on the day preceding each OGTT. IS following OGTTEE was significantly increased (10±2, P<0.05) compared to the OGTTN‐EX and SIE (5.6±2.5, 7.8±2.4, respectively), whereas OGTTSIE showed a strong trend (P<0.08) to be increased from OGTTN‐EX. These findings suggest that an acute bout of EE improves OGTTIS more than an acute bout of repeated SIE in normal healthy male subjects.