Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY.
Department of Kinesiology, California State University, Fresno, Fresno, CA.
Med Sci Sports Exerc. 2023 Jun 1;55(6):1069-1075. doi: 10.1249/MSS.0000000000003126. Epub 2023 Jan 14.
This study aimed to assess the V̇O 2 uptake obtained during a GXT and subsequent verification phase in untrained participants in a hot environment.
Twelve sedentary males completed a GXT followed by a biphasic supramaximal-load verification phase in a hot environment (39°C, 32% relative humidity). Rest between tests occurred in a temperate chamber and lasted until gastrointestinal temperature returned to baseline.
Mean verification phase V̇O 2max (37.8 ± 4.3 mL·kg -1 ·min -1 ) was lower than GXT (39.8 ± 4.1 mL·kg -1 ·min -1 ; P = 0.03) and not statistically equivalent. Using an individualized analysis approach, only 17% (2/12) of participants achieved a V̇O 2 plateau during the GXT. Verification phase confirmed GXT V̇O 2max in 100% of participants, whereas the traditional and the new age-dependent secondary V̇O 2max criteria indicated GXT V̇O 2max achievement at much lower rates (8/12 [67%] vs 7/12 [58%], respectively). Correlational indices between GXT and verification phase V̇O 2max were strong (intraclass correlation coefficient = 0.95, r = 0.86), and Bland-Altman analysis revealed a low mean bias of -2.1 ± 1.9 mL·kg -1 ·min -1 and 95% limits of agreement (-5.8 to 1.7 mL·kg -1 ·min -1 ).
Very few untrained males achieved a V̇O 2 plateau during GXT in the heat. When conducting GXT in a hot condition, the verification phase remains a valuable addition to confirm V̇O 2max in untrained males.
本研究旨在评估在热环境中未经训练的参与者进行递增负荷运动试验（GXT）和随后的验证阶段中 V̇O 2 的摄取量。
12 名久坐不动的男性在热环境（39°C，32%相对湿度）中完成 GXT 后，进行双相超最大负荷验证阶段。两次测试之间在温带室内休息，直到胃肠道温度恢复到基线。
平均验证阶段 V̇O 2max（37.8±4.3 mL·kg -1 ·min -1 ）低于 GXT（39.8±4.1 mL·kg -1 ·min -1 ；P=0.03），且不具有统计学等效性。使用个体化分析方法，只有 17%（2/12）的参与者在 GXT 期间达到了 V̇O 2 平台。验证阶段在 100%的参与者中确认了 GXT V̇O 2max，而传统和新的年龄依赖的次要 V̇O 2max 标准则表明 GXT V̇O 2max 的达成率低得多（8/12 [67%] 与 7/12 [58%]）。GXT 和验证阶段 V̇O 2max 之间的相关指数很强（组内相关系数=0.95，r=0.86），Bland-Altman 分析显示平均偏差为-2.1±1.9 mL·kg -1 ·min -1 ，95%一致性界限为（-5.8 至 1.7 mL·kg -1 ·min -1 ）。
在热环境中，很少有未经训练的男性在 GXT 中达到 V̇O 2 平台。当在热条件下进行 GXT 时，验证阶段仍然是确认未经训练男性 V̇O 2max 的有价值的补充。
