Department of Sports Medicine for Health Promotion, Tokyo Medical University, Tokyo, Japan.
Faculty of Science and Technology, Meijo University, Nagoya, Japan.
Adv Exp Med Biol. 2024;1463:347-351. doi: 10.1007/978-3-031-67458-7_56.
Near-infrared spectroscopy (NIRS) has been used to measure skeletal muscle oxidative function for more than 30 years. Several indicators evaluate muscle oxidative function using NIRS during exercise, such as deoxygenation rate at the start of exercise (Deoxy-rate), changes in deoxygenation during exercise (ΔDeoxy), and reoxygenation speed after exercise (T reoxy, reoxy rate). Previous studies have reported that these muscle NIRS indicators are significantly correlated with muscle fibre type, phosphocreatine recovery rate, and peak oxygen uptake. In addition, muscle NIRS indicators have been applied to the study of a number of chronic health conditions, including patients with ischaemic heart failure. Recently, wearable NIRS devices monitor muscle function continuously and freely in the field, and we predict that NIRS devices will be widely applied to our lifestyles more than ever before. However, there are some critical problems with measuring muscle oxidative function using NIRS devices. We have previously reported that subcutaneous adipose tissue thickness (SATT) greatly influences the light pathlength and makes it difficult to quantify tissue deoxygenation, especially in the measurements of muscle deoxygenation from the skin surface. The effects of SATT need to, therefore, be corrected when using NIRS devices, especially when comparing differences in sex, age, and trainability, as the subjects' SATT could differ significantly. In addition, we have more recently reported that assuming constant mean pathlength (MPL) in NIRS leads to an inaccurate interpretation of muscle deoxygenation, since there are greater changes in MPL during incremental cycling exercise, especially at shorter wavelengths in the NIRS region. In this mini-review, we will summarise the indicators of muscle oxidative function using NIRS and the challenges of using an NIRS apparatus, especially during exercise.
近红外光谱（NIRS）技术已经被用于测量骨骼肌氧化功能超过 30 年了。在运动过程中，有几个指标可以利用 NIRS 来评估肌肉的氧化功能，例如运动起始时的去氧率（Deoxy-rate）、运动过程中去氧的变化（ΔDeoxy）以及运动后复氧的速度（T reoxy，复氧率）。之前的研究已经表明，这些肌肉 NIRS 指标与肌肉纤维类型、磷酸肌酸恢复率和最大摄氧量显著相关。此外，肌肉 NIRS 指标已被应用于许多慢性健康状况的研究，包括缺血性心力衰竭患者。最近，可穿戴式 NIRS 设备可以在现场连续、自由地监测肌肉功能，我们预计 NIRS 设备将比以往任何时候都更广泛地应用于我们的生活方式。然而，利用 NIRS 设备测量肌肉氧化功能存在一些关键问题。我们之前曾报告过，皮下脂肪组织厚度（SATT）会极大地影响光程，使得量化组织去氧变得困难，特别是在从皮肤表面测量肌肉去氧的情况下。因此，在使用 NIRS 设备时，需要对 SATT 的影响进行校正，尤其是在比较性别、年龄和训练适应性差异时，因为受试者的 SATT 可能会有很大的差异。此外，我们最近还报告称，假设 NIRS 中的平均光程（MPL）不变会导致对肌肉去氧的不准确解释，因为在递增式自行车运动中 MPL 会发生更大的变化，尤其是在 NIRS 区域的较短波长下。在本篇迷你综述中，我们将总结利用 NIRS 测量肌肉氧化功能的指标以及使用 NIRS 仪器的挑战，尤其是在运动过程中。
