Central China Normal University, School of Physical Education and Sport, Wuhan, Hubei, China.
J Int Soc Sports Nutr. 2024 Dec;21(1):2409673. doi: 10.1080/15502783.2024.2409673. Epub 2024 Oct 1.
The effects of coffee ingestion on skeletal muscle microvascular function are not well understood. This study aimed to investigate the acute effects of coffee intake with varying levels of caffeine on skeletal muscle microvascular reactivity at rest and oxygen extraction during maximal incremental exercise in physically active individuals.
Twenty healthy young male participants were administered coffee with low caffeine (3 mg/kg body weight; LC), high caffeine (6 mg/kg body weight; HC), and placebo (decaf) in different sessions. Skeletal muscle reactivity indexes, including tissue saturation index 10s slope (TSI10) and TSI half time recovery (TSI ½) following 5-minute ischemia were measured at rest and were measured at baseline and post-coffee consumption using near-infrared spectroscopy (NIRS). Post-coffee intake, NIRS was also used to measure microvascular oxygen extraction during exercise via maximal incremental exercise. Peak oxygen consumption and peak power output (W) were simultaneously evaluated.
Post-coffee consumption, TSI10 was significantly higher in the LC condition compared to placebo ( = 0.001) and significantly higher in the HC condition compared to placebo ( < 0.001). However, no difference was detected between LC and HC conditions ( = 0.527). HC condition also showed significant less TSI ½ compared to placebo ( = 0.005). However, no difference was detected for microvascular oxygen extraction during exercise, despite the greater W found for HC condition ( < 0.001) compared to placebo.
Coffee ingestion with high caffeine level (6 mg/kg body weight) significantly enhanced skeletal muscle reactivity at rest. However, the improvement of exercise performance with coffee intake is not accompanied by alterations in muscle oxygen extraction.
咖啡摄入对骨骼肌微血管功能的影响尚不清楚。本研究旨在探讨在活跃个体中，摄入不同咖啡因水平的咖啡对静息状态下骨骼肌微血管反应性和最大递增运动期间氧摄取的急性影响。
20 名健康年轻男性参与者分别在不同时段摄入低咖啡因（3mg/kg 体重；LC）、高咖啡因（6mg/kg 体重；HC）和安慰剂（脱咖啡因）咖啡。使用近红外光谱（NIRS）在静息状态下测量 5 分钟缺血后组织饱和度指数 10 秒斜率（TSI10）和 TSI 半时间恢复（TSI ½）等骨骼肌反应指数，并在摄入咖啡后和摄入咖啡后测量基线和 TSI ½。摄入咖啡后，NIRS 还用于通过最大递增运动测量运动期间的微血管氧摄取。同时评估峰值耗氧量和峰值功率输出（W）。
摄入咖啡后，LC 条件下 TSI10 明显高于安慰剂（ = 0.001），HC 条件下明显高于安慰剂（ < 0.001）。然而，LC 和 HC 条件之间没有差异（ = 0.527）。HC 条件下 TSI ½ 也明显低于安慰剂（ = 0.005）。然而，尽管 HC 条件下的 W 明显高于安慰剂（ < 0.001），但运动期间的微血管氧摄取没有差异。
摄入高咖啡因水平（6mg/kg 体重）的咖啡可显著增强静息状态下的骨骼肌反应性。然而，咖啡摄入对运动表现的改善并未伴随着肌肉氧摄取的改变。
