Introduction

A huge number of COVID-19 patients should be referred to rehabilitation programmes. Individualizing the exercise intensity by metabolic response provide good physiological results. The aim of this study was to investigate the validity of EMG as a non-invasive determinant of the anaerobic threshold and respiratory compensation point, for more precise exercise intensity prescription.

Methods

An observational cross-sectional study with 66 recovered COVID-19 patients was carried out. The patients underwent a cardiopulmonary exercise test with simultaneous assessment of muscle electromyography in vastus lateralis. EMG breakpoints were analyzed during the ramp-up protocol. The first and second EMG breakpoints were used for anaerobic threshold and respiratory compensation point determination.

Results

EMG and gas exchange analysis presented strong correlation in anaerobic threshold (r = 0.97, p < 0.0001) and respiratory compensation point detection (r = 0.99, p < 0.0001) detection. Bland-Altman analysis demonstrated a bias = −4.7 W (SD = 6.2 W, limits of agreement = −16.9 to 7.6) for anaerobic threshold detection in EMG compared to gas exchange analysis. In respiratory compensation point detection, Bland-Altman analysis demonstrated a bias = -2.1 W (SD = 4.5 W, limits of agreement = −10.9 to 6.6) in EMG compared to gas exchange analysis. EMG demonstrated a small effect size compared to gas exchange analysis in oxygen uptake and power output at anaerobic threshold and respiratory compensation point detection.

Conclusions

EMG analysis detects anaerobic threshold and respiratory compensation point without clinical significant difference than gas exchange analysis (gold standard method) in recovered COVID-19 patients.

中文翻译：

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检测 COVID-19 康复患者无氧阈和呼吸代偿点的肌电图断点

介绍

应将大量 COVID-19 患者转诊至康复计划。通过代谢反应个性化运动强度提供了良好的生理结果。本研究的目的是调查肌电图作为无氧阈值和呼吸补偿点的非侵入性决定因素的有效性，以便更精确地制定运动强度处方。

方法

对 66 名康复的 COVID-19 患者进行了一项观察性横断面研究。患者接受了心肺运动试验，同时评估了股外侧肌的肌电图。在启动协议期间分析了 EMG 断点。第一个和第二个 EMG 断点用于确定无氧阈和呼吸补偿点。

结果

肌电图和气体交换分析在无氧阈值 (r = 0.97, p < 0.0001) 和呼吸补偿点检测 (r = 0.99, p < 0.0001) 检测中表现出很强的相关性。Bland-Altman 分析表明，与气体交换分析相比，EMG 中厌氧阈值检测的偏差 = −4.7 W（SD = 6.2 W，一致限度 = −16.9 至 7.6）。在呼吸补偿点检测中，Bland-Altman 分析表明与气体交换分析相比，EMG 中的偏差 = -2.1 W（SD = 4.5 W，一致限度 = -10.9 至 6.6）。与气体交换分析相比，肌电图在无氧阈值和呼吸补偿点检测的摄氧量和功率输出方面的影响较小。

结论

EMG 分析检测出 COVID-19 康复患者的无氧阈和呼吸代偿点，与气体交换分析（金标准法）相比无临床显着差异。