Harris M Brennan, Kuo Chia-Hua
Department of Health Sciences, College of William and Mary, Williamsburg, VA, United States.
Laboratory of Exercise Biochemistry, College of Kinesiology, University of Taipei, Taipei, Taiwan.
Front Physiol. 2021 Jul 6;12:685166. doi: 10.3389/fphys.2021.685166. eCollection 2021.
Exercise training decreases abdominal fat in an intensity-dependent manner. The fat loss effect of exercise has been intuitively thought to result from increased fat burning during and after exercise, defined by conversion of fatty acid into carbon dioxide in consumption of oxygen. Nevertheless, increasing exercise intensity decreases oxidation of fatty acids derived from adipose tissue despite elevated lipolysis. The unchanged 24-h fatty acid oxidation during and after exercise does not provide support to the causality between fat burning and fat loss. In this review, alternative perspectives to explain the fat loss outcome are discussed. In brief, carbon and nitrogen redistribution to challenged tissues (muscle and lungs) for fuel replenishment and cell regeneration against abdominal adipose tissue seems to be the fundamental mechanism underlying the intensity-dependent fat loss effect of exercise. The magnitude of lipolysis (fatty acid release from adipocytes) and the amount of post-meal carbon and nitrogen returning to abdominal adipose tissue determines the final fat tissue mass. Therefore, meal arrangement at the time when muscle has the greatest reconstruction demand for carbon and nitrogen could decrease abdominal fat accumulation while increasing muscle mass and tissue repair.
运动训练以强度依赖的方式减少腹部脂肪。运动的减脂效果一直被直观地认为是运动期间及运动后脂肪燃烧增加所致，脂肪燃烧定义为脂肪酸在消耗氧气过程中转化为二氧化碳。然而，尽管脂肪分解增加，但运动强度的增加会降低源自脂肪组织的脂肪酸氧化。运动期间及运动后24小时脂肪酸氧化未发生变化，这并不支持脂肪燃烧与脂肪减少之间的因果关系。在本综述中，我们讨论了解释减脂结果的其他观点。简而言之，碳和氮重新分配至受挑战的组织（肌肉和肺）以补充燃料并对抗腹部脂肪组织进行细胞再生，这似乎是运动强度依赖的减脂效果的根本机制。脂肪分解的程度（脂肪酸从脂肪细胞释放）以及餐后返回腹部脂肪组织的碳和氮的量决定了最终的脂肪组织质量。因此，在肌肉对碳和氮有最大重建需求时安排饮食，可减少腹部脂肪堆积，同时增加肌肉质量和组织修复。
