Oxygen uptake during the last bouts of exercise incorporated into high-intensity intermittent cross-exercise exceeds the V̇O2max of the same exercise mode.

Autor: Yuzhong Xu, Xin Liu, Katsunori Tsuji, Takafumi Hamaoka, Izumi Tabata
Předmět:
Zdroj: Sports Medicine & Health Science (SMHS); Mar2024, Vol. 6 Issue 1, p63-69, 7p
Abstrakt: Oxygen uptake (V̇ O2) was measured during a non-exhaustive high-intensity intermittent cross-exercise (HIICE) protocol consisting of four alternating bouts of 20 s running (R) and three bouts of bicycle exercise (BE) at ~160% and ~170% maximal oxygen uptake (V̇ O2max), respectively, with 10 s between-bout rests (sequence R-BE-R-BER-BE-R). The V̇ O2 during the last BE ([52.2 ± 5.0] mL.kg-1 .min-1 ) was significantly higher than the V̇ O2max of the BE ([48.0 ± 5.4] mL.kg-1 .min-1, n = 30) and similar to that of running. For clarifying the underlying mechanisms, a corresponding HIICE-protocol with BE and arm cranking ergometer exercise (AC) was used (sequence AC-AC-BE-AC-BE-AC-AC-BE). In some experiments, thigh blood flow was occluded by a cuff around the upper thigh. Without occlusion, the V̇ O2 during the AC ([39.2 ± 7.1] mL.kg-1 .min-1 [6th bout]) was significantly higher than the V̇ O2max of AC ([30.2 ± 4.4] mL.kg-1 .min-1, n = 7). With occlusion, the corresponding V̇ O2 ([29.8 ± 3.9] mL.kg-1 .min-1 ) was reduced to that of the V̇ O2max of AC and significantly less than the V̇ O2 without occlusion. These findings suggest that during the last bouts of HIICE may exceed the of the specific exercise, probably because it is a summation of the V̇ O2 for the ongoing exercise plus excess post-oxygen consumption (EPOC) produced by the previous exercise with a higher V̇ O2max. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index