Institute for Health and Sport (IHES), Victoria University, Melbourne, VIC, Australia.
Australia Institute of Sport, Canberra, ACT, Australia.
FASEB J. 2021 May;35(5):e21499. doi: 10.1096/fj.202002205RR.
The microvasculature is important for both health and exercise tolerance in a range of populations. However, methodological limitations have meant changes in microvascular blood flow are rarely assessed in humans during interventions designed to affect skeletal muscle blood flow such as the wearing of compression garments. The aim of this study is, for the first time, to use contrast-enhanced ultrasound to directly measure the effects of compression on muscle microvascular blood flow alongside measures of femoral artery blood flow and muscle oxygenation following intense exercise in healthy adults. It was hypothesized that both muscle microvascular and femoral artery blood flows would be augmented with compression garments as compared with a control condition. Ten recreationally active participants completed two repeated-sprint exercise sessions, with and without lower-limb compression tights. Muscle microvascular blood flow, femoral arterial blood flow (2D and Doppler ultrasound), muscle oxygenation (near-infrared spectroscopy), cycling performance, and venous blood samples were measured/taken throughout exercise and the 1-hour post-exercise recovery period. Compared with control, compression reduced muscle microvascular blood volume and attenuated the exercise-induced increase in microvascular velocity and flow immediately after exercise and 1 hour post-exercise. Compression increased femoral artery diameter and augmented the exercise-induced increase in femoral arterial blood flow during exercise. Markers of blood oxygen extraction in muscle were increased with compression during and after exercise. Compression had no effect on blood lactate, glucose, or exercise performance. We provide new evidence that lower-limb compression attenuates the exercise-induced increase in skeletal muscle microvascular blood flow following exercise, despite a divergent increase in femoral artery blood flow. Decreased muscle microvascular perfusion is offset by increased muscle oxygen extraction, a potential mechanism allowing for the maintenance of exercise performance.
微血管系统对于多种人群的健康和运动耐量都非常重要。然而，由于方法学上的限制，在旨在影响骨骼肌血流的干预措施中，如穿着压缩服，很少有研究能检测到微血管血流的变化。本研究的目的是首次使用对比增强超声直接测量在健康成年人进行剧烈运动后，与压迫状态相比，压迫对肌肉微血管血流和股动脉血流以及肌肉氧合的影响。假设与对照条件相比，压迫会增加肌肉微血管和股动脉的血流量。10 名有规律运动的参与者完成了两次重复冲刺运动测试，一次穿着下肢压缩紧身衣，一次不穿。在运动过程中和运动后 1 小时的恢复期间，测量/采集了肌肉微血管血流、股动脉血流（二维和多普勒超声）、肌肉氧合（近红外光谱）、骑行表现和静脉血样。与对照相比，压迫减少了肌肉微血管容积，并在运动后立即和运动后 1 小时减弱了运动引起的微血管速度和流量增加。压迫增加了股动脉直径，并在运动期间增强了运动引起的股动脉血流增加。运动中和运动后，肌肉中的血氧提取标志物随压迫而增加。压迫对血乳酸、血糖或运动表现没有影响。我们提供了新的证据，表明下肢压迫尽管股动脉血流增加，但会减弱运动后骨骼肌微血管血流的增加。肌肉微血管灌注减少被肌肉氧摄取增加所抵消，这可能是维持运动表现的一种潜在机制。
