Attenuated Metabolic and Cardiorespiratory Responses to Isoenergetic High-Intensity Interval Exercise of Short Versus Long Bouts

Purpose To compare the metabolic, cardiorespiratory and perceptual responses to three isoenergetic high-intensity interval exercise (HIIE) protocols of different bout duration and an isoenergetic continuous exercise protocol. Methods Eleven healthy males (age, 28 ± 6 yr) performed four 20-min cycling trials of equal mean power output 1 wk apart. Participants cycled either continuously (CON) or intermittently with 10 s (HIIE10), 30 s (HIIE30), or 60 s (HIIE60) bouts at intensities corresponding to 49% (CON) or 100% of power at peak oxygen uptake (V̇O2peak). Recovery intervals during the HIIE trials were 15, 45, and 90 s, respectively. Results Average V̇O2 was similar in the HIIE trials (2.29 ± 0.42, 2.20 ± 0.43, and 2.12 ± 0.45 L·min−1, for HIIE10, HIIE30, and HIIE60, respectively), whereas in CON (2.02 ± 0.38 L·min−1), it was lower than HIIE10 (P = 0.002) and HIIE30 (P = 0.043). Average pulmonary ventilation (VE) was higher in HIIE60 compared with HIIE10, HIIE30, and CON (75.8 ± 21.8 L·min−1 vs 64.1 ± 14.5 L·min−1, 64.1 ± 16.2 L·min−1, and 54.0 ± 12.5 L·min−1, respectively, P
Source: Medicine and Science in Sports and Exercise - Category: Sports Medicine Tags: APPLIED SCIENCE Source Type: research