Izumi Kazuma, Yamamori Keisuke, Katayama Keisho, Kano Yutaka, Tanaka Noriko, Akima Hiroshi
Graduate School of Education and Human Development, Nagoya University, Nagoya, Aichi, Japan.
Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Aichi, Japan.
Exp Physiol. 2025 Jan;110(1):106-114. doi: 10.1113/EP091948. Epub 2024 Dec 10.
Power Doppler ultrasonography is used to measure blood flow within a given muscle, otherwise known as intramuscular blood flow. However, it is not fully understood how intramuscular blood flow and muscle oxygenation change with repetitive muscle contraction. The present study was conducted to assess changes in intramuscular blood flow and muscle oxygenation of the vastus lateralis (VL) during intermittent and incremental contractions. Fifteen healthy male subjects (21.7 ± 2.6 years) performed intermittent (5 s contraction, 5 s relaxation) and incremental isometric knee extensions at 30%, 40%, 50%, 60% and 70% of maximal voluntary contraction (MVC) until task failure. Intramuscular blood flow and muscle oxygen saturation ( ) were simultaneously measured using power Doppler ultrasonography and near-infrared spectroscopy, respectively, from the right VL of the mid-thigh. Intramuscular blood flow was increased from 0.5 ± 0.5% at rest to 13.9 ± 9.5% at task failure. Intramuscular blood flow significantly increased from rest to 30% and 40% MVC (P = 0.001), and significantly decreased from 30% to 70% MVC (P = 0.004). These results indicate that intramuscular blood flow and show different patterns of change, suggesting that the contribution of intramuscular blood flow to oxygen supply decreases within the VL at moderate and higher exercise intensities.
能量多普勒超声用于测量特定肌肉内的血流，即肌内血流。然而，目前尚不完全清楚肌内血流和肌肉氧合如何随重复性肌肉收缩而变化。本研究旨在评估股外侧肌（VL）在间歇性和递增性收缩过程中肌内血流和肌肉氧合的变化。15名健康男性受试者（21.7±2.6岁）进行间歇性（5秒收缩，5秒放松）和递增性等长伸膝运动，强度分别为最大自主收缩（MVC）的30%、40%、50%、60%和70%，直至任务失败。分别使用能量多普勒超声和近红外光谱法同时测量大腿中部右侧VL的肌内血流和肌肉氧饱和度（ ）。肌内血流从静息时的0.5±0.5%增加到任务失败时的13.9±9.5%。肌内血流从静息到30%和40%MVC时显著增加（P = 0.001），而从30%到70%MVC时 显著降低（P = 0.004）。这些结果表明，肌内血流和 呈现不同的变化模式，提示在中等及更高运动强度下，股外侧肌内肌内血流对氧气供应的贡献降低。
