Rothschild Jeffrey, Earnest Conrad P
TriFit Performance Center, Santa Monica, CA 90404, USA.
Exercise and Sport Nutrition Laboratory, Texas A&M University, College Station, TX 77843, USA.
J Funct Morphol Kinesiol. 2018 Jul 25;3(3):41. doi: 10.3390/jfmk3030041.
The role of an athlete's dietary intake (both timing and food type) goes beyond simply providing fuel to support the body's vital processes. Nutritional choices also have an impact on the metabolic adaptations to training. Over the past 20 years, research has suggested that strategically reducing carbohydrate (CHO) availability during an athlete's training can modify the metabolic responses in lieu of simply maintaining a high CHO diet. Several methods have been explored to manipulate CHO availability and include: Low-carb, high-fat (LCHF) diets, performing two-a-day training without glycogen restoration between sessions, and a "sleep-low" approach entailing a glycogen-depleting session in the evening without consuming CHO until after a morning training session performed in an overnight fasted state. Each of these methods can confer beneficial metabolic adaptations for the endurance athlete including increases in mitochondrial enzyme activity, mitochondrial content, and rates of fat oxidation, yet data showing a direct performance benefit is still unclear.
运动员饮食摄入（包括时间和食物类型）的作用不仅仅是简单地提供能量以支持身体的重要生理过程。营养选择对训练引起的代谢适应也有影响。在过去20年中，研究表明，在运动员训练期间有策略地减少碳水化合物（CHO）的可利用量，可改变代谢反应，而不是简单地维持高碳水化合物饮食。人们探索了几种控制碳水化合物可利用量的方法，包括：低碳水化合物、高脂肪（LCHF）饮食；每天进行两次训练，且两次训练之间不进行糖原恢复；以及“夜间低糖”方法，即在晚上进行一次耗尽糖原的训练，直到在空腹过夜状态下进行晨练后才摄入碳水化合物。这些方法中的每一种都能为耐力运动员带来有益的代谢适应，包括线粒体酶活性、线粒体含量和脂肪氧化率的增加，但表明有直接运动表现益处的数据仍不明确。
