Impairments in muscle microvascular function are associated with the pathogenesis of sarcopenia and cardiovascular disease. High-intensity interval training (HIIT) is an intervention by which a myriad of beneficial skeletal muscle/cardiovascular adaptations have been reported across age, including capillarisation and improved endothelial function. Herein, we hypothesised that HIIT would enhance muscle microvascular blood flow and vascular reactivity to acute contractile activity in older adults, reflecting HIIT-induced vascular remodelling. In a randomised controlled-trial, twenty-five healthy older adults aged 65–85 years (mean BMI 27.0) were randomised to 6-week HIIT or a no-intervention control period of an equal duration. Measures of microvascular responses to a single bout of muscle contractions (i.e. knee extensions) were made in the m. vastus lateralis using contrast-enhanced ultrasound during a continuous intravenous infusion of Sonovue™ contrast agent, before and after the intervention period, with concomitant assessments of cardiorespiratory fitness and resting blood pressure. HIIT led to improvements in anaerobic threshold (13.2 ± 3.4 vs. 15.3 ± 3.8 ml/kg/min, P < 0.001), dynamic exercise capacity (145 ± 60 vs. 159 ± 59 W, P < 0.001) and resting (systolic) blood pressure (142 ± 15 vs. 133 ± 11 mmHg, P < 0.01). Notably, HIIT elicited significant increases in microvascular blood flow responses to acute contractile activity (1.8 ± 0.63 vs. 2.3 ± 0.8 (arbitrary contrast units (AU), P < 0.01)), with no change in any of these parameters observed in the control group. Six weeks HIIT improves skeletal muscle microvascular responsiveness to acute contractile activity in the form of active hyperaemia-induced by a single bout of resistance exercise. These findings likely reflect reports of enhanced large vessel distensibility, improved endothelial function, and muscle capillarisation following HIIT. Moreover, our findings illustrate that HIIT may be effective in mitigating deleterious alterations in muscle microvascular mediated aspects of sarcopenia.

肌肉微血管功能受损与肌肉减少症和心血管疾病的发病机制有关。高强度间歇训练 (HIIT) 是一种干预措施，据报道，通过该干预措施，各种年龄的骨骼肌/心血管适应能力会有所改善，包括毛细血管化和改善内皮功能。在此，我们假设 HIIT 会增强老年人肌肉微血管血流和血管对急性收缩活动的反应性，反映 HIIT 诱导的血管重塑。在一项随机对照试验中，25 名 65-85 岁的健康老年人（平均 BMI 27.0）被随机分配到 6 周的 HIIT 或相同持续时间的无干预控制期。对单次肌肉收缩（即膝关节伸展）的微血管反应的测量是在米。股外侧肌在干预期前后连续静脉输注 Sonovue™ 造影剂期间使用对比增强超声，同时评估心肺健康和静息血压。HIIT 改善了无氧阈值（13.2 ± 3.4 vs. 15.3 ± 3.8 ml/kg/min，P < 0.001）、动态运动能力（145 ± 60 vs. 159 ± 59 W，P < 0.001）和静息（收缩压）血压（142 ± 15 对 133 ± 11 mmHg，P < 0.01）。值得注意的是，HIIT 引起微血管血流对急性收缩活动的反应显着增加（1.8 ± 0.63 对 2.3 ± 0.8（任意对比单位 (AU)，P < 0.01）），在对照组中观察到的任何这些参数都没有变化团体。六周的 HIIT 改善了骨骼肌微血管对急性收缩活动的反应，表现为单次抗阻运动引起的活动性充血。这些发现可能反映了 HIIT 后大血管扩张性增强、内皮功能改善和肌肉毛细血管化的报告。此外，我们的研究结果表明，HIIT 可能有效减轻肌肉减少症的肌肉微血管介导方面的有害改变。