Schwarz Neil A, Blahnik Zachary J, Prahadeeswaran Srihari, McKinley-Barnard Sarah K, Holden Shelley L, Waldhelm Andy
Department of Health, Kinesiology, and Sport, University of South Alabama, Mobile, AL, United States.
Department of Physical Therapy, University of South Alabama, Mobile, AL, United States.
Front Nutr. 2018 Dec 21;5:132. doi: 10.3389/fnut.2018.00132. eCollection 2018.
The purpose of the study was to determine if cycling exercise combined with (-)-epicatechin supplementation was more effective at increasing training adaptations than cycling combined with a placebo. Blood and muscle samples were obtained at rest before and after training to determine the effects of (-)-epicatechin supplementation on total serum antioxidant capacity, skeletal muscle mitochondrial protein content, and skeletal muscle myostatin gene expression. Participants ( = 20) completed two testing sessions separated by 4 weeks of cycle training, with supplementation of 100 mg (200 mg total daily) of (-)-epicatechin or a placebo, twice daily. Data were analyzed using a two-way mixed model ANOVA for each variable and the alpha level was set at ≤ 0.05. A significant increase was observed for time for relative peak anaerobic power ( < 0.01), relative anaerobic capacity ( < 0.01), and fatigue index ( < 0.01). A significant increase was observed for time for absolute peak VO ( < 0.01) and peak power output obtained during the peak VO test ( < 0.01). A significant interaction between group and time for relative peak VO was observed ( = 0.04). Relative peak VO significantly increased over time in the placebo group ( < 0.01), but not in the (-)-epicatechin group ( = 0.21). A significant increase was observed for time for total serum antioxidant capacity ( = 0.01). No interaction or main effect of time was observed for myostatin ( > 0.05). Likewise, no interaction or main effect of time was observed for cytochrome C or citrate synthase ( > 0.05). A significant interaction effect was observed for succinate dehydrogenase (SDH; = 0.02). SDH content increased significantly for the placebo group ( = 0.03, partial η = 0.59), but not for the (-)-epicatechin group ( = 0.81). Further, whereas no difference existed between the groups for SDH at baseline ( = 0.23), SDH content was significantly greater in the placebo group at the post time point ( = 0.01). Results indicate that (-)-epicatechin supplementation does not affect myostatin gene expression or anaerobic training adaptations but inhibits aerobic and mitochondrial SDH adaptations to cycle exercise training.
本研究的目的是确定与补充安慰剂相比，骑行运动联合补充（-）-表儿茶素是否在增强训练适应性方面更有效。在训练前后静息状态下采集血液和肌肉样本，以确定补充（-）-表儿茶素对血清总抗氧化能力、骨骼肌线粒体蛋白含量和骨骼肌肌生长抑制素基因表达的影响。参与者（n = 20）完成了两次测试，两次测试间隔4周的骑行训练，期间每日两次补充100 mg（总计每日200 mg）的（-）-表儿茶素或安慰剂。对每个变量使用双向混合模型方差分析进行数据分析，α水平设定为p≤0.05。相对峰值无氧功率时间（p<0.01）、相对无氧能力（p<0.01）和疲劳指数（p<0.01）出现显著增加。绝对峰值VO₂时间（p<0.01）和在峰值VO₂测试期间获得的峰值功率输出（p<0.01）出现显著增加。观察到相对峰值VO₂的组与时间之间存在显著交互作用（p = 0.04）。安慰剂组中相对峰值VO₂随时间显著增加（p<0.01），但在（-）-表儿茶素组中未增加（p = 0.21）。血清总抗氧化能力时间出现显著增加（p = 0.01）。肌生长抑制素未观察到时间的交互作用或主效应（p>0.05）。同样，细胞色素C或柠檬酸合酶也未观察到时间的交互作用或主效应（p>0.05）。琥珀酸脱氢酶（SDH）观察到显著的交互作用效应（p = 0.02）。安慰剂组的SDH含量显著增加（p = 0.03，偏η² = 0.59），但（-）-表儿茶素组未增加（p = 0.81）。此外，尽管两组在基线时SDH无差异（p = 0.23），但在后期时间点安慰剂组的SDH含量显著更高（p = 0.01）。结果表明，补充（-）-表儿茶素不影响肌生长抑制素基因表达或无氧训练适应性，但抑制有氧和线粒体SDH对骑行运动训练的适应性。
