RELATIONSHIP BETWEEN BODY AND LEG VO2 DURING MAXIMAL CYCLE ERGOMETRY
RELATIONSHIP BETWEEN BODY AND LEG VO2 DURING MAXIMAL CYCLE ERGOMETRY
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DOI：
10.1152/jappl.1992.73.3.1114
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发表时间：
1992-09-01
影响因子：
3.3
通讯作者：
WAGNER, PD
中科院分区：
文献类型：
--
作者：
KNIGHT, DR;POOLE, DC;WAGNER, PD
目前尚不清楚在最大工作率（WR）下全身耗氧量（VO 2）的渐近行为是否可以用运动腿中VO 2的类似行为来解释。为了解决这个问题，同时测量身体和腿部VO 2在次最大和最大水平的努力呼吸常氧和低氧气体在7名训练有素的男性自行车运动员（最大VO 2 64.7 +/- 2.7 ml O2.min-1.kg-1），每个人都表现出一个可重复的VO 2-WR渐近线在疲劳增量踏车测力计。通过恒定输注热稀释法测量左腿血流量，并将腿部总VO 2计算为两次腿部血流量和桡动脉-股静脉O2浓度差的乘积。将在次最大WR下确定的VO 2-WR关系外推至最大WR，作为评估身体和腿部VO 2反应的基础。实测和外推最大VO 2之间的差异为235 +/- 45（身体）和203 +/- 70（腿部）ml O2/min（无显著差异）。腿部VO 2的平台期与腿部血流和O2提取以及腿部VO 2的平台期相关，并由其解释。我们的结论是，全身VO 2在最大WRs的渐近行为是在行使腿VO 2配置文件的直接反映。
It is not known whether the asymptotic behavior of whole body O2 consumption (VO2) at maximal work rates (WR) is explained by similar behavior of VO2 in the exercising legs. To resolve this question, simultaneous measurements of body and leg VO2 were made at submaximal and maximal levels of effort breathing normoxic and hypoxic gases in seven trained male cyclists (maximal VO2 64.7 +/- 2.7 ml O2.min-1.kg-1), each of whom demonstrated a reproducible VO2-WR asymptote during fatiguing incremental cycle ergometry. Left leg blood flow was measured by constant-infusion thermodilution, and total leg VO2 was calculated as the product of twice leg flow and radial arterial-femoral venous O2 concentration difference. The VO2-WR relationships determined at submaximal WR's were extrapolated to maximal WR as a basis for assessing the body and leg VO2 responses. The differences between measured and extrapolated maximal VO2 were 235 +/- 45 (body) and 203 +/- 70 (leg) ml O2/min (not significantly different). Plateauing of leg VO2 was associated with, and explained by, plateauing of both leg blood flow and O2 extraction and hence of leg VO2. We conclude that the asymptotic behavior of whole body VO2 at maximal WRs is a direct reflection of the VO2 profile at the exercising legs.