Miles F Bartlett, Andrew P Oneglia, Delaney Davis, Sauyeh Zamani, Ashfaq Siddiqui, Mark D Ricard, Michael D Nelson
{"title":"最大努力的膝关节伸展运动损害骨骼肌氧化能力和体内VO2的恢复。","authors":"Miles F Bartlett, Andrew P Oneglia, Delaney Davis, Sauyeh Zamani, Ashfaq Siddiqui, Mark D Ricard, Michael D Nelson","doi":"10.1152/japplphysiol.00517.2025","DOIUrl":null,"url":null,"abstract":"<p><p>In the present study, we examined how fatiguing exercise affects O<sub>2</sub>-based measures of skeletal muscle oxidative capacity in vivo by measuring changes in the rate constant of muscle V̇o<sub>2</sub> recovery ([Formula: see text]). Healthy young adults completed isokinetic (120°·s<sup>-1</sup>), maximal voluntary dynamic contractions (MVDCs) lasting 24 (baseline [Formula: see text]) and 240 s (postfatiguing exercise [Formula: see text]). Vastus lateralis [Formula: see text] was measured using near-infrared diffuse correlation spectroscopy (NIRS-DCS) via the conventional repeated arterial occlusion method (<i>part A</i>, <i>n</i> = 14) or a novel NIRS-DCS \"free-flow\" method (<i>part B</i>, <i>n</i> = 13). Pulmonary V̇o<sub>2</sub> (pV̇o<sub>2</sub>), muscle V̇o<sub>2</sub> (mV̇o<sub>2</sub>), and surface electromyography (sEMG) measures of muscle activation were also measured throughout the 240-s trial. Compared with the 24-s trial, [Formula: see text] following 240 s of MVDCs was impaired by ∼25% (<i>part A</i>; <i>P</i> = 0.005) and ∼16% (<i>part B</i>; <i>P</i> = 0.017). Moreover, both pV̇o<sub>2</sub> and mV̇o<sub>2</sub> rapidly increased to maximal levels, where they remained for the duration of the 240-s trial, despite sEMG activity and peak MVDC power declining. These results demonstrate that fatiguing exercise not only impairs O<sub>2</sub>-based measures of skeletal muscle oxidative capacity, but also that mitochondrial O<sub>2</sub> consumption is uncoupled from power output and ATP demand during fatiguing exercise.<b>NEW & NOTEWORTHY</b> We measured rates of skeletal muscle V̇o<sub>2</sub> recovery ([Formula: see text]) at baseline and following fatiguing exercise using near-infrared diffuse correlation spectroscopy (NIRS-DCS). Regardless of whether [Formula: see text] was measured via the conventional repeated arterial occlusion method (<i>part A</i>) or a novel NIRS-DCS \"free-flow\" method (<i>part B</i>), fatiguing exercise impaired [Formula: see text] by ∼15%-25%. Because ATP demand rapidly declines post exercise, the slow [Formula: see text] recovery observed here suggests fatiguing exercise may uncouple the functional relationship between mitochondrial O<sub>2</sub> consumption and ATP synthase activity.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":" ","pages":"1073-1089"},"PeriodicalIF":3.3000,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Maximal-effort knee-extension exercise impairs skeletal muscle oxidative capacity and V̇o<sub>2</sub> recovery in vivo.\",\"authors\":\"Miles F Bartlett, Andrew P Oneglia, Delaney Davis, Sauyeh Zamani, Ashfaq Siddiqui, Mark D Ricard, Michael D Nelson\",\"doi\":\"10.1152/japplphysiol.00517.2025\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>In the present study, we examined how fatiguing exercise affects O<sub>2</sub>-based measures of skeletal muscle oxidative capacity in vivo by measuring changes in the rate constant of muscle V̇o<sub>2</sub> recovery ([Formula: see text]). Healthy young adults completed isokinetic (120°·s<sup>-1</sup>), maximal voluntary dynamic contractions (MVDCs) lasting 24 (baseline [Formula: see text]) and 240 s (postfatiguing exercise [Formula: see text]). Vastus lateralis [Formula: see text] was measured using near-infrared diffuse correlation spectroscopy (NIRS-DCS) via the conventional repeated arterial occlusion method (<i>part A</i>, <i>n</i> = 14) or a novel NIRS-DCS \\\"free-flow\\\" method (<i>part B</i>, <i>n</i> = 13). Pulmonary V̇o<sub>2</sub> (pV̇o<sub>2</sub>), muscle V̇o<sub>2</sub> (mV̇o<sub>2</sub>), and surface electromyography (sEMG) measures of muscle activation were also measured throughout the 240-s trial. Compared with the 24-s trial, [Formula: see text] following 240 s of MVDCs was impaired by ∼25% (<i>part A</i>; <i>P</i> = 0.005) and ∼16% (<i>part B</i>; <i>P</i> = 0.017). Moreover, both pV̇o<sub>2</sub> and mV̇o<sub>2</sub> rapidly increased to maximal levels, where they remained for the duration of the 240-s trial, despite sEMG activity and peak MVDC power declining. These results demonstrate that fatiguing exercise not only impairs O<sub>2</sub>-based measures of skeletal muscle oxidative capacity, but also that mitochondrial O<sub>2</sub> consumption is uncoupled from power output and ATP demand during fatiguing exercise.<b>NEW & NOTEWORTHY</b> We measured rates of skeletal muscle V̇o<sub>2</sub> recovery ([Formula: see text]) at baseline and following fatiguing exercise using near-infrared diffuse correlation spectroscopy (NIRS-DCS). Regardless of whether [Formula: see text] was measured via the conventional repeated arterial occlusion method (<i>part A</i>) or a novel NIRS-DCS \\\"free-flow\\\" method (<i>part B</i>), fatiguing exercise impaired [Formula: see text] by ∼15%-25%. Because ATP demand rapidly declines post exercise, the slow [Formula: see text] recovery observed here suggests fatiguing exercise may uncouple the functional relationship between mitochondrial O<sub>2</sub> consumption and ATP synthase activity.</p>\",\"PeriodicalId\":15160,\"journal\":{\"name\":\"Journal of applied physiology\",\"volume\":\" \",\"pages\":\"1073-1089\"},\"PeriodicalIF\":3.3000,\"publicationDate\":\"2025-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of applied physiology\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://doi.org/10.1152/japplphysiol.00517.2025\",\"RegionNum\":3,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/9/18 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q1\",\"JCRName\":\"PHYSIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of applied physiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1152/japplphysiol.00517.2025","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/9/18 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
Maximal-effort knee-extension exercise impairs skeletal muscle oxidative capacity and V̇o2 recovery in vivo.
In the present study, we examined how fatiguing exercise affects O2-based measures of skeletal muscle oxidative capacity in vivo by measuring changes in the rate constant of muscle V̇o2 recovery ([Formula: see text]). Healthy young adults completed isokinetic (120°·s-1), maximal voluntary dynamic contractions (MVDCs) lasting 24 (baseline [Formula: see text]) and 240 s (postfatiguing exercise [Formula: see text]). Vastus lateralis [Formula: see text] was measured using near-infrared diffuse correlation spectroscopy (NIRS-DCS) via the conventional repeated arterial occlusion method (part A, n = 14) or a novel NIRS-DCS "free-flow" method (part B, n = 13). Pulmonary V̇o2 (pV̇o2), muscle V̇o2 (mV̇o2), and surface electromyography (sEMG) measures of muscle activation were also measured throughout the 240-s trial. Compared with the 24-s trial, [Formula: see text] following 240 s of MVDCs was impaired by ∼25% (part A; P = 0.005) and ∼16% (part B; P = 0.017). Moreover, both pV̇o2 and mV̇o2 rapidly increased to maximal levels, where they remained for the duration of the 240-s trial, despite sEMG activity and peak MVDC power declining. These results demonstrate that fatiguing exercise not only impairs O2-based measures of skeletal muscle oxidative capacity, but also that mitochondrial O2 consumption is uncoupled from power output and ATP demand during fatiguing exercise.NEW & NOTEWORTHY We measured rates of skeletal muscle V̇o2 recovery ([Formula: see text]) at baseline and following fatiguing exercise using near-infrared diffuse correlation spectroscopy (NIRS-DCS). Regardless of whether [Formula: see text] was measured via the conventional repeated arterial occlusion method (part A) or a novel NIRS-DCS "free-flow" method (part B), fatiguing exercise impaired [Formula: see text] by ∼15%-25%. Because ATP demand rapidly declines post exercise, the slow [Formula: see text] recovery observed here suggests fatiguing exercise may uncouple the functional relationship between mitochondrial O2 consumption and ATP synthase activity.
期刊介绍:
The Journal of Applied Physiology publishes the highest quality original research and reviews that examine novel adaptive and integrative physiological mechanisms in humans and animals that advance the field. The journal encourages the submission of manuscripts that examine the acute and adaptive responses of various organs, tissues, cells and/or molecular pathways to environmental, physiological and/or pathophysiological stressors. As an applied physiology journal, topics of interest are not limited to a particular organ system. The journal, therefore, considers a wide array of integrative and translational research topics examining the mechanisms involved in disease processes and mitigation strategies, as well as the promotion of health and well-being throughout the lifespan. Priority is given to manuscripts that provide mechanistic insight deemed to exert an impact on the field.