营销话术证据 B · meta 分析
空腹有氧减脂更快
真相
把比例当成了绝对量; 决定减脂的是 24 小时总能量差, 不是训练那一刻烧的是糖还是脂肪。
这话术为什么会流行
它有一个真实的观察垫底 —— 空腹时脂肪供能的比例确实更高。把“比例更高”读成“减得更多”只差一步, 而这一步在健身房里几乎没人拦。
机制速览
Zone 2 常被和健身房器械上的fat burn zone混在一起, 但这是两件事。营销话术说: 中低强度 (60-70% 最大心率) 是脂肪燃烧区, 强度高了烧的是糖不是脂肪, 所以减脂就该在这区间练。
来源（3）
- Achten, J., & Jeukendrup, A. E. (2003). Maximal fat oxidation during exercise in trained men. International Journal of Sports Medicine, 24(8), 603-608. Max fat-oxidation occurs around 59-64% VO2max; above that the absolute fat-oxidation rate falls even as relative % rises — the empirical basis for debunking the 'fat-burning zone' marketing.
- Coyle, E. F. (1995). Substrate utilization during exercise in active people. The American Journal of Clinical Nutrition, 61(4 Suppl), 968S-979S. Classic dataset on the fat/carbohydrate oxidation cross-over with intensity — the empirical basis for the Zone 2 'fat-burning' framing (and the limits of that framing).
- Brooks, G. A. (2018). The science and translation of lactate shuttle theory. Cell Metabolism, 27(4), 757-785. Definitive modern review establishing lactate as fuel rather than waste; the 'lactic acid burn' framing is anatomically and biochemically incorrect.