Carter Helen, Jones Andrew M, Maxwell Neil S, Doust Jonathan H
University of Surrey Roehampton, London, UK.
J Sports Sci. 2002 Nov;20(11):901-9. doi: 10.1080/026404102320761796.
The aim of this study was to examine the variability of the oxygen uptake (VO2) kinetic response during moderate- and high-intensity treadmill exercise within the same day (at 06:00, 12:00 and 18:00 h) and across days (on five occasions). Nine participants (age 25 +/- 8 years, mass 70.2 +/- 4.7 kg, VO2max 4137 +/- 697 ml x min(-1); mean +/- s) took part in the study. Six of the participants performed replicate 'square-wave' rest-to-exercise transitions of 6 min duration at running speeds calculated to require 80% VO2 at the ventilatory threshold (moderate-intensity exercise) and 50% of the difference between VO2 at the ventilatory threshold and VO2max (50% delta; high-intensity exercise) on 5 different days. Although the amplitudes of the VO2 response were relatively constant (coefficient of variation approximately 6%) from day to day, the time-based parameters were more variable (coefficient of variation approximately 15 to 30%). All nine participants performed replicate square-waves for each time of day. There was no diurnal effect on the time-based parameters of VO2 kinetics during either moderate- or high-intensity exercise. However, for high-intensity exercise, the amplitude of the primary component was significantly lower during the 12:00 h trial (2859 +/- 142 ml x min(-1) vs 2955 +/- 135 ml x min(-1) at 06:00 h and 2937 +/- 137 ml x min(-1) at 18:00 h; P < 0.05), but this effect was eliminated when expressed relative to body mass. The results of this study indicate that the amplitudes of the VO2 kinetic responses to moderate- and high-intensity treadmill exercise are similar within and across test days. The time-based parameters, however, are more variable from day to day and multiple transitions are, therefore, recommended to increase confidence in the data.
本研究的目的是考察同一天内（06:00、12:00和18:00）以及不同日期（共五次）在中高强度跑步机运动期间摄氧量（VO₂）动力学反应的变异性。九名参与者（年龄25±8岁，体重70.2±4.7 kg，VO₂max为4137±697 ml·min⁻¹；均值±标准差）参与了本研究。其中六名参与者在5个不同日期，以计算得出的、在通气阈值时需80%VO₂的跑步速度（中等强度运动）以及通气阈值时VO₂与VO₂max差值的50%（50%Δ；高强度运动），进行了时长6分钟的重复“方波”从休息到运动的转换。尽管VO₂反应的幅度在不同日期相对恒定（变异系数约为6%），但基于时间的参数变异性更大（变异系数约为15%至30%）。所有九名参与者在每天的每个时间点都进行了重复方波测试。在中等强度或高强度运动期间，VO₂动力学的基于时间的参数均无昼夜效应。然而，对于高强度运动，在12:00的测试中，主要成分的幅度显著较低（2859±142 ml·min⁻¹，而06:00时为2955±135 ml·min⁻¹，18:00时为2937±137 ml·min⁻¹；P<0.05），但以体重为参照时，这种效应消失。本研究结果表明，中高强度跑步机运动的VO₂动力学反应幅度在测试日内和不同测试日之间相似。然而，基于时间的参数在不同日期变异性更大，因此建议进行多次转换以提高数据的可信度。
