Effects of Different Isometric Exercise Modalities on Microvascular and Metabolic Function

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation Pub Date : 2025-10-13 DOI:10.1111/micc.70031

Minyoung Kwak, Brian Benitez, Clara J. Mitchinson, Erik R. Snell, Haley C. Bergstrom

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引用次数: 0

Abstract

Objective

This study compared near-infrared spectroscopy (NIRS)-derived microvascular function, muscle oxygenation (SmO₂) dynamics, and fatigability during sustained isometric forearm flexion under two conditions: a rating of perceived exertion (RPE) level of 3 (RPE-Clamp) versus a constant torque (CT) matched to the torque produced during the first second of RPE-Clamp.

Methods

Thirteen healthy males (22.2 ± 4.7 year) completed both tasks on separate days. SmO₂ was measured during exercise, maximal voluntary isometric contractions (MVIC) were performed before and after exercise, and time to task failure (TTF) was recorded. Vascular occlusion tests (VOT) were used to assess microvascular function pre- and post-exercise.

Results

CT induced significantly greater performance fatigability than RPE-Clamp (p < 0.001), despite similar TTF (p = 0.171). SmO₂ significantly decreased during early (p = 0.001) and final (p = 0.028) phases of CT, while increasing during mid (p < 0.001) phases in RPE-Clamp. Post-VOT indicated a significantly reduced desaturation rate (slope 1; p < 0.001), a greater extent of tissue hypoxia (minimum SmO₂; p = 0.003), and increased microvascular reactivity (slope 2; p = 0.021) than pre-VOT, with greater peak re-saturation (MaxSmO₂; p = 0.010) observed in CT than RPE-Clamp.

Conclusions

Despite greater fatigability and desaturation in CT, both exercise modalities may enhance microvascular reactivity. Prolonged isometric exercise and subsequent hypoxic stress may contribute to a reduced desaturation rate post-exercise.

Abstract Image

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不同等长运动方式对微血管和代谢功能的影响。

目的：本研究比较了近红外光谱（NIRS）衍生的微血管功能、肌肉氧合（SmO2）动力学和持续等距前臂屈曲在两种情况下的疲劳程度：感知用力（RPE）等级为3 （RPE- clamp）与恒定扭矩（CT）相匹配的RPE- clamp第一秒产生的扭矩。方法：13名健康男性（22.2±4.7岁）在不同的日期完成两项任务。运动时测量SmO2，运动前后测量最大自主等长收缩（MVIC），记录任务失败时间（TTF）。血管闭塞试验（VOT）用于评估运动前后微血管功能。结果：CT诱导的疲劳性能明显高于RPE-Clamp (p值在CT早期（p = 0.001）和末期（p = 0.028）降低，在CT中期（p值p = 0.003）升高，微血管反应性（斜率2；p = 0.021）高于vot前，峰值再饱和度（MaxSmO2; p = 0.010）高于RPE-Clamp。结论：尽管CT表现出更大的疲劳和去饱和，但两种运动方式都可以增强微血管反应性。长时间的等长运动和随后的低氧应激可能有助于降低运动后的去饱和率。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Microcirculation 医学-外周血管病

CiteScore

5.00

自引率

4.20%

发文量

审稿时长

6-12 weeks

期刊介绍： The journal features original contributions that are the result of investigations contributing significant new information relating to the vascular and lymphatic microcirculation addressed at the intact animal, organ, cellular, or molecular level. Papers describe applications of the methods of physiology, biophysics, bioengineering, genetics, cell biology, biochemistry, and molecular biology to problems in microcirculation. Microcirculation also publishes state-of-the-art reviews that address frontier areas or new advances in technology in the fields of microcirculatory disease and function. Specific areas of interest include: Angiogenesis, growth and remodeling; Transport and exchange of gasses and solutes; Rheology and biorheology; Endothelial cell biology and metabolism; Interactions between endothelium, smooth muscle, parenchymal cells, leukocytes and platelets; Regulation of vasomotor tone; and Microvascular structures, imaging and morphometry. Papers also describe innovations in experimental techniques and instrumentation for studying all aspects of microcirculatory structure and function.