Holloway Tanya M, Snijders Tim, VAN Kranenburg Janneau, VAN Loon Luc J C, Verdijk Lex B
NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, THE NETHERLANDS.
Med Sci Sports Exerc. 2018 Jan;50(1):36-45. doi: 10.1249/MSS.0000000000001409.
Although endurance exercise training promotes angiogenesis and improves metabolic health, the effect of resistance training on this process is less well defined. We hypothesized that capillarization would increase proportionally, and concurrently, with muscle fiber hypertrophy in response to resistance training in young men.
In this double-blind, randomized control trial, 36 men (22 ± 1 yr) were randomized to placebo or protein supplementation, and participated in 12 wk of resistance training. Skeletal muscle biopsies were collected before and after 2, 4, 8, and 12 wk of training. Immunohistochemistry assessed fiber type-specific size and capillarization. Western blot and reverse transcription polymerase chain reaction assessed proteins involved in the molecular regulation of angiogenesis.
Resistance training effectively increased Type I (15% ± 4%; P < 0.01) and Type II fiber cross-sectional area (28% ± 5%; P < 0.0001), an effect that tended to be further enhanced with protein supplementation in Type II fibers (P = 0.078). Capillary-to-fiber ratio significantly increased in Type I (P = 0.001) and II (P = 0.015) fibers after 12 wk of resistance exercise training and was evident after only 2 wk. Capillary-to-fiber perimeter exchange index increased in the Type I fibers only (P = 0.054) after 12 wk of training. Training resulted in a reduction in vascular endothelial growth factor mRNA. A (P = 0.008), while vascular endothelial growth factor receptor 2 (P = 0.016), hypoxia-inducible factor 1α (P = 0.016), and endothelial nitric oxide synthase (P = 0.01) increased in both groups. Hypoxia-inducible factor 1α protein content was higher in the protein group (main group effect, P = 0.02), and endothelial nitric oxide synthase content demonstrated a divergent relationship (time-group interaction, P = 0.049).
This study presents novel evidence that microvascular adaptations and the molecular pathways involved are elevated after 2 wk of a 12-wk resistance training program. Increases in muscle fiber cross-sectional area are effectively matched by the changes in the microvasculature, providing further support for resistance training programs to optimize metabolic health.
尽管耐力运动训练可促进血管生成并改善代谢健康，但抗阻训练对这一过程的影响尚不清楚。我们假设，在年轻男性进行抗阻训练时，毛细血管化会随着肌肉纤维肥大而相应增加。
在这项双盲随机对照试验中，36名男性（22±1岁）被随机分为安慰剂组或蛋白质补充组，并参加为期12周的抗阻训练。在训练的第2、4、8和12周前后采集骨骼肌活检样本。免疫组织化学评估纤维类型特异性大小和毛细血管化。蛋白质印迹法和逆转录聚合酶链反应评估参与血管生成分子调控的蛋白质。
抗阻训练有效地增加了I型纤维横截面积（15%±4%；P<0.01）和II型纤维横截面积（28%±5%；P<0.0001），在II型纤维中，蛋白质补充倾向于进一步增强这一效果（P=0.078）。抗阻运动训练12周后，I型（P=0.001）和II型（P=0.015）纤维的毛细血管与纤维比例显著增加，且仅在2周后就很明显。训练12周后，仅I型纤维的毛细血管与纤维周长交换指数增加（P=0.054）。训练导致血管内皮生长因子mRNA水平降低（P=0.008），而两组中的血管内皮生长因子受体2（P=0.016）、缺氧诱导因子1α（P=0.016）和内皮型一氧化氮合酶（P=0.01）均增加。蛋白质组中缺氧诱导因子1α蛋白含量更高（主要组效应，P=0.02），内皮型一氧化氮合酶含量呈现不同关系（时间-组交互作用，P=0.049）。
本研究提供了新的证据，表明在为期12周的抗阻训练计划进行2周后，微血管适应性及相关分子途径增强。肌肉纤维横截面积的增加与微血管的变化有效匹配，为优化代谢健康的抗阻训练计划提供了进一步支持。
