Early dynamics of O2 uptake and heart rate as affected by exercise work rate.
Early dynamics of O2 uptake and heart rate as affected by exercise work rate.
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受运动工作率影响的氧气吸收和心率的早期动态。
DOI：
10.1152/jappl.1989.67.6.2535
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Wasserman,K
中科院分区：
文献类型：
--
作者：
Sietsema,KE;Daly,JA;Wasserman,K
恒定工频运动的摄氧量(Vo2)和心率(HR)的动力学特征是两个阶段，一个是即刻反应，主要是血液动力学突然变化的结果；另一个是反应减慢，主要是血流量和动静脉O2差(AvDo2)增加的结果。关于第一阶段的VO2和HR，以及它们的动力学与工作速度和强度之间的关系的报道很少。由于第一阶段的反应依赖于心血管的突然调整，因此假设VO2和HR的第一阶段增加越大，受试者越“合适”，并且相对独立于工作效率。为了验证这一点，10名正常受试者从休息到从无负荷自行车到150W的五种工作速度的每一种都进行了锻炼。VO2、HR和VO2/HR的I期增加与工作速度有很小但显著的相关性，但与体能无关。在非常低的工作速率(无负荷循环和25W)下，VO2和HR在第一阶段经常超过其稳态水平。因此，在这些工作速率下，VO2或HR没有第二阶段的增加，整个氧气需求已经通过第一阶段的循环调节得到满足。对于所有其他工作速率，Vo2和HR的平均反应时间与健康有关，并且比Vo2/HR慢，这表明avDo2先于心输出量达到稳定状态。
The kinetics of O2 uptake (Vo2) and heart rate (HR) in response to constant work rate exercise have been characterized as two phases, an immediate response as the result largely of abrupt hemodynamic changes and a slower response as the result of increases in both blood flow and arteriovenous O2 difference (avDo2). There are few data reported concerning Vo2 and HR during phase I or the relationship between their kinetics and work rate or intensity. Because phase I responses depend on abrupt cardiovascular adjustments, it was hypothesized that phase I increases in Vo2 and HR would be greater the more “fit” the subject and would be relatively independent of work rate. To test this, 10 normal subjects exercised from rest to each of five work rates ranging from unloaded cycling to 150 W. The phase I increases of Vo2, HR, and Vo2/HR had small but significant correlations with work rate but not with fitness. At very low work rates (unloaded cycling and 25 W), Vo2 and HR often exceeded their steady-state levels in phase I. There was therefore no phase II increase for Vo2 or HR at these work rates, the entire O2 requirement having been met by phase I circulatory adjustments. For all other work rates, mean response times for Vo2 and HR were related to fitness and were slower than those for Vo2/HR, suggesting that avDo2 reached a steady state before cardiac output did.