School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada.
J Appl Physiol (1985). 2021 May 1;130(5):1460-1469. doi: 10.1152/japplphysiol.00945.2020. Epub 2021 Mar 11.
Work of breathing ([Formula: see text]) derived from a single lung volume and pleural pressure is limited and does not fully characterize the mechanical work done by the respiratory musculature. It has long been known that abdominal activation increases with increasing exercise intensity, yet the mechanical work done by these muscles is not reflected in [Formula: see text]. Using optoelectronic plethysmography (OEP), we sought to show first that the volumes obtained from OEP (V) were comparable to volumes obtained from flow integration (V) during cycling and running, and second, to show that partitioned volume from OEP could be utilized to quantify the mechanical work done by the rib cage ([Formula: see text]) and abdomen ([Formula: see text]) during exercise. We fit 11 subjects (6 males/5 females) with reflective markers and balloon catheters. Subjects completed an incremental ramp cycling test to exhaustion and a series of submaximal running trials. We found good agreement between V versus V during cycling (bias = 0.002; > 0.05) and running (bias = 0.016; > 0.05). From rest to maximal exercise,[Formula: see text] increased by 84% (range: 30%-99%; [Formula: see text]: 1 ± 1 J/min to 61 ± 52 J/min). The relative contribution of the abdomen increased from 17 ± 9% at rest to 26 ± 16% during maximal exercise. Our study highlights and provides a quantitative measure of the role of the abdominal muscles during exercise. Incorporating the work done by the abdomen allows for a greater understanding of the mechanical tasks required by the respiratory muscles and could provide further insight into how the respiratory system functions during disease and injury. We demonstrated that optoelectronic plethysmography (OEP) is a reliable tool to determine ventilatory volume changes during cycling and running, without restricting natural upper arm movements. Second, using OEP volumes coupled with pressure-derived measures, we calculated the work done by the rib cage and abdomen, respectively, during exercise. Collectively, our findings indicate that pulmonary mechanics can be accurately quantified using OEP, and abdominal work performed during ventilation contributes substantially to the overall work of the respiratory musculature.
呼吸功（[公式：见正文]）由单个肺容积和胸膜压力衍生而来，具有局限性，无法全面描述呼吸肌完成的机械功。人们早就知道，随着运动强度的增加，腹部活动会增加，但这些肌肉所做的机械功并没有反映在[公式：见正文]中。本研究使用光电体积描记法（OEP），旨在首先证明 OEP 获得的容积（V）与在骑行和跑步过程中通过流量积分获得的容积（V）具有可比性，其次，证明可以利用 OEP 分割容积来定量测量呼吸肌在运动过程中对胸廓（[公式：见正文]）和腹部（[公式：见正文]）做功。我们让 11 名被试（6 男/5 女）佩戴反光标记和气球导管。被试完成了递增负荷的踏车至力竭测试和一系列次最大跑步测试。我们发现，在骑行（偏差=0.002；>0.05）和跑步（偏差=0.016；>0.05）过程中，V 与 V 之间具有良好的一致性。从休息到最大运动强度，[公式：见正文]增加了 84%（范围：30%-99%；[公式：见正文]：1±1J/min 到 61±52J/min）。腹部的相对贡献从休息时的 17±9%增加到最大运动时的 26±16%。本研究强调并提供了一种定量测量腹部肌肉在运动过程中作用的方法。纳入腹部做功可以更好地理解呼吸肌完成的机械任务，并深入了解呼吸系统在疾病和损伤时的功能。我们证明，光电体积描记法（OEP）是一种可靠的工具，可在骑行和跑步时确定通气容积变化，而不会限制自然的上臂运动。其次，我们使用 OEP 容积和压力衍生的测量值，分别计算了胸廓和腹部在运动过程中的做功。总的来说，我们的研究结果表明，使用 OEP 可以准确量化肺力学，并且通气过程中腹部做功对呼吸肌的整体做功有很大贡献。
