The impact of elevated body core temperature on critical power as determined by a 3-min all-out test.
The impact of elevated body core temperature on critical power as determined by a 3-min all-out test.
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通过 3 分钟全力测试确定身体核心温度升高对临界功率的影响。
DOI：
10.1152/japplphysiol.00253.2021
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Minson,ChristopherT
中科院分区：
文献类型：
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作者：
Kaiser,BrendanW;Kruse,Ka'eoK;Gibson,BrandonM;Santisteban,KelseyJ;Larson,EmilyA;Wilkins,BradW;Jones,AndrewM;Halliwill,JohnR;Minson,ChristopherT
临界功率(Cp)划定了大强度和剧烈运动强度区域，持续高于Cp的工作速率会导致摄氧量达到最大值，从而达到运动耐力极限。Cp以上的有限功W‘由功率-持续时间关系的曲率常数定义。在炎热的环境中进行大强度或剧烈的运动会产生额外的挑战，这与体温(TC)的升高有关，这可能会影响CP和W‘。本研究的目的是确定升高的Tcon CP和W‘的影响。在循环测功机上进行3分钟的“全力”试验，分别用末试验功率(EP；最后30名S的平均数)和末试验功率以上的工作(WEP)来估算CP和W‘。志愿者(n=8，4名女性)在一次熟悉访问和两次实验访问(热中和热，随机交叉设计)中进行了3分钟的测试。在实验3分钟测试之前，受试者在水中浸泡(温度：36°C，30分钟；热：40.5°C，直到Tcis≥38.5°C)。热状态下的平均TC显著高于热中温状态(38.5±0.0°C vs.37.4±0.2°C；均值±SD，P<0.01)。所有3分钟的测试都在环境舱中进行[温度：18°C，相对湿度(RH)为45%；热：38 °C，RH为40%]。热电(239±57W)和热电(234±66W；P=0.55)条件下的EP相近。温热条件下WEP(10.9±3.0kJ)与高温条件下(9.3±3.6；P=0.19)相似。这些结果表明，升高的TchA对EP或WEP没有显著影响。NEW和NOTEWORTHY由3min全量试验估算的功率-持续关系的参数(临界功率和W‘)与体温中和条件相比不受体温升高的影响。
Critical power (CP) delineates the heavy and severe exercise intensity domains, and sustained work rates above CP result in an inexorable progression of oxygen uptake to a maximal value and, subsequently, the limit of exercise tolerance. The finite work capacity above CP, W′, is defined by the curvature constant of the power-duration relationship. Heavy or severe exercise in a hot environment generates additional challenges related to the rise in body core temperature (Tc) that may impact CP and W′. The purpose of this study was to determine the effect of elevated Tcon CP and W′. CP and W′ were estimated by end-test power (EP; mean of final 30 s) and work above end-test power (WEP), respectively, from 3-min “all-out” tests performed on a cycle ergometer. Volunteers (n= 8, 4 female) performed the 3-min tests during a familiarization visit and two experimental visits (thermoneutral vs. hot, randomized crossover design). Before experimental 3-min tests, the subjects were immersed in water (thermoneutral: 36°C for 30 min; hot: 40.5°C until Tcwas ≥38.5°C). Mean Tcwas significantly greater in the hot condition than in the thermoneutral condition (38.5 ± 0.0°C vs. 37.4 ± 0.2°C; means ± SD,P< 0.01). All 3-min tests were performed in an environmental chamber [thermoneutral: 18°C, 45% relative humidity (RH); hot: 38 °C, 40% RH]. EP was similar between thermoneutral (239 ± 57 W) and hot (234 ± 66 W;P= 0.55) conditions. WEP was similar between thermoneutral (10.9 ± 3.0 kJ) and hot conditions (9.3 ± 3.6;P= 0.19). These results suggest that elevated Tchas no significant impact on EP or WEP.NEW & NOTEWORTHYThe parameters of the power-duration relationship (critical power and W′) estimated by a 3-min all-out test were not altered by elevated body core temperature as compared with a thermoneutral condition.