Quirion A, Brisson G R, Laurencelle L, DeCarufel D, Audet A, Dulac S, Ledoux M, Vogelaere P
Département des sciences de l'activité physique, Université du Québec à Trois-Rivières, Canada.
Eur J Appl Physiol Occup Physiol. 1988;57(2):192-7. doi: 10.1007/BF00640662.
This study was designed to clarify the effects of dietary modifications on the lactate threshold (LT) and on the onset of blood lactate accumulation (OBLA) during progressive incremental exercise. Six healthy males volunteered for the study. Informed consent was obtained from every participant. The following protocol was administered to each subject on three occasions: a 48-h period of mixed dieting (53% carbohydrates, 30% lipids, 17% proteins) preceding the first exercise test, immediately followed by a 48-h period of either a carbohydrate-rich (68% CHO, 23% lipids, 9% proteins) or a fat-rich (19% CHO, 57% lipids, 26% proteins) iso-caloric diet leading to the second exercise and separated from the third test by a 12-days period. Exercise tests were conducted on an electrically-braked ergocycle, and consisted of a progressive incremental maximal exercise. Respiratory parameters were continuously monitored by an automated open circuit sampling system. Exercise blood lactate (LA), free fatty acids (FFA), glucose levels and acid-base balance were determined from venous blood samples obtained through an indwelling brachial catheter. Peak lactate values, workload and performance time were not significantly altered by imposed diets. Furthermore, dietary modifications had no significant effect on LT, OBLA fixed at 4 mmol and ventilatory threshold. Increased pH and FFA mobilization were observed with fat-rich diet, while CHO-rich diet markedly increased the respiratory exchange ratio (R). It is concluded that LT and OBLA are not significantly altered by fat or CHO enrichment of diets.
本研究旨在阐明饮食调整对递增运动期间乳酸阈（LT）和血乳酸开始积累（OBLA）的影响。六名健康男性自愿参与本研究。每位参与者均签署了知情同意书。对每位受试者进行了三次如下方案：在第一次运动测试前进行48小时的混合饮食（碳水化合物53%、脂质30%、蛋白质17%），随后立即进行48小时富含碳水化合物（CHO 68%、脂质23%、蛋白质9%）或富含脂肪（CHO 19%、脂质57%、蛋白质26%）的等热量饮食，以进行第二次运动，并在第三次测试前间隔12天。运动测试在电动刹车的测力计上进行，包括递增运动至最大运动。通过自动开路采样系统连续监测呼吸参数。从通过留置肱静脉导管采集的静脉血样中测定运动时的血乳酸（LA）、游离脂肪酸（FFA）、葡萄糖水平和酸碱平衡。所施加的饮食对乳酸峰值、工作量和运动时间没有显著影响。此外，饮食调整对LT、固定在4 mmol的OBLA和通气阈没有显著影响。富含脂肪的饮食可观察到pH值升高和FFA动员增加，而富含碳水化合物的饮食显著增加了呼吸交换率（R）。得出的结论是，饮食中脂肪或碳水化合物的增加不会显著改变LT和OBLA。
