Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada.
PLoS One. 2019 Jul 25;14(7):e0220192. doi: 10.1371/journal.pone.0220192. eCollection 2019.
It has been demonstrated that the plateau in the near-infrared spectroscopy (NIRS) derived deoxygenated hemoglobin and myoglobin (deoxy[Hb+Mb]) signal (i.e., deoxy[Hb+Mb]PLATEAU) towards the end of a ramp-incremental (RI) test does not represent the upper-limit in O2 extraction of the vastus lateralis (VL) muscle, given that an O2 extraction reserve has been recently observed. This study aimed to investigate whether this O2 extraction reserve was present in various populations and whether it exhibited sex- and/or training- related differences.Sixteen men- 8 untrained (27±5 years; 83±11 kg; 179±9 cm), 8 trained (27±4 years; 82±10 kg; 182±8 cm) and 9 trained women (27±2 years; 66±10 kg; 172±6 cm) performed a RI cycling test to exhaustion. The NIRS-derived deoxy[Hb+Mb] signal was measured continuously on the VL as a proxy for O2 extraction. A leg blood flow occlusion (i.e., ischemia) was performed at rest (LBFOCC 1) and immediately post the RI test (LBFOCC 2).No significant difference was found between the deoxy[Hb+Mb] amplitude during LBFOCC 1 and the deoxy[Hb+Mb]PLATEAU (p>0.05) nor between baseline (bsln) deoxy[Hb+Mb] values. deoxy[Hb+Mb] amplitude during LBFOCC 2 was significantly greater than LBFOCC 1 and at deoxy[Hb+Mb]PLATEAU (p<0.05) with group means ~30-45% higher than the deoxy[Hb+Mb]PLATEAU and LBFOCC 1 (p<0.05). No significant differences were found between groups in O2 extraction reserve, regardless of sex- or training-statusThe results of this study demonstrated the existence of an O2 extraction reserve in different populations, and that neither sex- nor training-related differences affect the amplitude of the reserve.
已经证明，在斜坡递增（RI）测试结束时近红外光谱（NIRS）衍生的去氧血红蛋白和肌红蛋白（去氧[Hb+Mb]）信号（即去氧[Hb+Mb]PLATEAU）没有达到股外侧肌（VL）的最大氧提取量，因为最近观察到了氧提取储备。本研究旨在探讨这种氧提取储备是否存在于不同人群中，以及它是否表现出与性别和/或训练相关的差异。
16 名男性-8 名未训练（27±5 岁；83±11 公斤；179±9 厘米），8 名训练（27±4 岁；82±10 公斤；182±8 厘米）和 9 名训练有素的女性（27±2 岁；66±10 公斤；172±6 厘米）进行了 RI 循环测试直至力竭。连续测量 VL 上的 NIRS 衍生去氧[Hb+Mb]信号作为氧提取的替代指标。在休息时（LBFOCC 1）和 RI 测试后立即（LBFOCC 2）进行腿部血流闭塞（即缺血）。
在 LBFOCC 1 期间的去氧[Hb+Mb]幅度和去氧[Hb+Mb]PLATEAU 之间没有发现显著差异（p>0.05），也没有在基线（bsln）去氧[Hb+Mb]值之间发现差异。LBFOCC 2 期间的去氧[Hb+Mb]幅度明显大于 LBFOCC 1 和去氧[Hb+Mb]PLATEAU（p<0.05），组平均值比去氧[Hb+Mb]PLATEAU 和 LBFOCC 1 高约 30-45%（p<0.05）。无论性别或训练状态如何，各组之间的氧提取储备均无差异。
本研究的结果表明，不同人群中存在氧提取储备，且性别和训练相关差异均不会影响储备的幅度。
