Gender differences in substrate utilization during submaximal exercise in endurance-trained subjects
Gender differences in substrate utilization during submaximal exercise in endurance-trained subjects
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DOI：
10.1152/ajpendo.00266.2001
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发表时间：
2002-02-01
影响因子：
5.1
通讯作者：
Kiens, B
中科院分区：
文献类型：
--
作者：
Roepstorff, C;Steffensen, CH;Kiens, B
通过应用动静脉导管插入术、稳定同位素和肌肉活检，研究了 7 名接受过耐力训练的男性和 7 名接受过耐力训练、月经正常的女性在 90 分钟的自行车运动期间，在 58% 峰值摄氧量（(V) 超过 dotO(2 峰值)）期间腿部的底物利用率。根据每公斤去脂体重（V）超过 dotO（2 峰值）、身体活动水平和受试者的训练历史来匹配女性和男性组。实验前 8 天，所有受试者食用相同的饮食，营养成分和能量含量得到良好控制，所有女性均在月经周期的卵泡中期进行测试。运动期间，女性和男性的呼吸交换比（RER）和腿部呼吸商（RQ）相似。雄性中肌细胞三酰甘油 (TG) 的降解可以忽略不计，但雌性中的肌细胞三酰甘油 (TG) 降解达到 12.4 +/- 3.2 mmol/kg 干重，分别相当于雌性和雄性总摄氧量的 25.0 +/- 6.0 和 5.0 +/- 7.3% (P < 0.05)。女性和男性的血浆脂肪酸（12.0 +/- 2.5 和 9.6 +/- 1.5%）、血糖（13.6 +/- 1.5 和 14.3 +/- 1.5%）和糖原（48.5 +/- 4.9 和 42.8 +/- 2.1%）的利用率相似。因此，在女性中，测得的底物氧化占腿部摄氧量的 99%，而在男性中，测得的氧化脂质底物占腿部摄氧量的 28%。这些发现可能表明男性利用了额外的脂质来源，可能是极低密度脂蛋白-TG或位于肌纤维之间的TG。根据 RER 和腿部 RQ，得出的结论是，在相同相对工作量的次最大运动期间，碳水化合物和脂质对腿部氧化代谢的相对贡献不存在性别差异。然而，不同脂质来源的利用似乎存在性别影响。
Substrate utilization across the leg during 90 min of bicycle exercise at 58% of peak oxygen uptake ((V) over dotO(2 peak)) was studied in seven endurance-trained males and seven endurance-trained, eumenorrheic females by applying arteriovenous catheterization, stable isotopes, and muscle biopsies. The female and male groups were matched according to (V) over dotO(2 peak) per kilogram of lean body mass, physical activity level, and training history of the subjects. All subjects consumed the same diet, well controlled in terms of nutrient composition as well as energy content, for 8 days preceding the experiment, and all females were tested in the midfollicular phase of the menstrual cycle. During exercise, respiratory exchange ratio (RER) and leg respiratory quotient (RQ) were similar in females and males. Myocellular triacylglycerol (TG) degradation was negligible in males but amounted to 12.4 +/- 3.2 mmol/kg dry wt in females and corresponded to 25.0 +/- 6.0 and 5.0 +/- 7.3% of total oxygen uptake in females and males, respectively (P < 0.05). Utilization of plasma fatty acids (12.0 +/- 2.5 and 9.6 +/- 1.5%), blood glucose (13.6 +/- 1.5 and 14.3 +/- 1.5%), and glycogen (48.5 +/- 4.9 and 42.8 +/- 2.1%) were similar in females and males. Thus, in females, measured substrate oxidation accounted for 99% of the leg oxygen uptake, whereas in males 28% of leg oxygen uptake was unaccounted for in terms of measured oxidized lipid substrates. These findings may indicate that males utilized additional lipid sources, presumably very low density lipoprotein-TG or TG located between muscle fibers. On the basis of RER and leg RQ, it is concluded that no gender difference existed in the relative contribution from carbohydrate and lipids to the oxidative metabolism across the leg during submaximal exercise at the same relative workload. However, an effect of gender appears to occur in the utilization of the different lipid sources.