Miller Joshua M, Housh Terry J, Coburn Jared W, Cramer Joel T, Johnson Glen O
Department of Health and Human Performance, University of Nebraska-Lincoln, 68506, USA.
J Strength Cond Res. 2004 Aug;18(3):618-24. doi: 10.1519/13243.1.
The purpose of this study was 3-fold: (a) to determine if the mathematical model used to estimate the electromyographic fatigue threshold (EMGFT) and physical working capacity at the heart rate threshold (PWCHRT) could be applied to VO2 measurements, (b) to propose a new fatigue threshold called the physical working capacity at the oxygen consumption threshold (PWCVO2), and (c) to compare the power output at the PWCVO2 to those of the EMGFT, PWCHRT, and ventilatory threshold (VT). Fifteen adult volunteers (mean age +/- SD = 22 +/- 2 years) performed a maximal cycle ergometer test to determine VO2peak and VT as well as 4 8-minute submaximal work bouts for the determination of PWCHRT, EMGFT, and PWCVO2. A 1-way repeated measures analysis of variance (ANOVA) with Tukey post hoc comparison indicated that PWCHRT (84 +/- 36) was significantly (p < 0.05) less than EMGFT (126 +/- 51), but there were no differences for PWCVO2 (111 +/- 44) and VT (111 +/- 60) versus PWCHRT or EMGFT. The results of this study indicated that (a) the mathematical model used to determine the PWCHRT and EMGFT was applicable to the measurement of VO2 and could be used to estimate the PWCVO2 during cycle ergometry, (b) there was a difference in the mean power outputs that corresponded to the fatigue thresholds determined from EMG and heart rate measurements, and (c) the PWCVO2 test may provide a useful submaximal technique for estimating the VT.
(a) 确定用于估计肌电图疲劳阈值(EMGFT)和心率阈值时的身体工作能力(PWCHRT)的数学模型是否可应用于VO₂测量;(b) 提出一种新的疲劳阈值,即耗氧量阈值时的身体工作能力(PWCVO₂);(c) 比较PWCVO₂时的功率输出与EMGFT、PWCHRT和通气阈值(VT)时的功率输出。15名成年志愿者(平均年龄±标准差 = 22±2岁)进行了最大运动强度的蹬车测试,以确定VO₂峰值和VT,以及4次8分钟的次最大运动负荷测试,用于确定PWCHRT、EMGFT和PWCVO₂。采用单因素重复测量方差分析(ANOVA)并进行Tukey事后比较,结果表明PWCHRT(84±36)显著低于EMGFT(126±51)(p < 0.05),但PWCVO₂(111±44)和VT(111±60)与PWCHRT或EMGFT相比无差异。本研究结果表明:(a) 用于确定PWCHRT和EMGFT的数学模型适用于VO₂测量,可用于估计蹬车运动时的PWCVO₂;(b) 对应于从肌电图和心率测量确定的疲劳阈值的平均功率输出存在差异;(c) PWCVO₂测试可能为估计VT提供一种有用的次最大运动技术。