Zdzieblik Denise, Friesenborg Hilke, Gollhofer Albert, König Daniel
Department for Nutrition, Institute for Sports and Sports Science, University of Freiburg, Freiburg, Germany.
Centre for Sports Science and University Sports, Department for Nutrition, Exercise and Health, University of Vienna, Vienna, Austria.
Front Nutr. 2022 Apr 11;9:802374. doi: 10.3389/fnut.2022.802374. eCollection 2022.
Consuming low glycemic carbohydrates leads to an increased muscle fat utilization and preservation of intramuscular glycogen, which is associated with improved flexibility to metabolize either carbohydrates or fats during endurance exercise. The purpose of this trial was to investigate the effect of a 4-week high fat low carbohydrate (HFLC-G: ≥65% high glycemic carbohydrates per day; = 9) vs. high carbohydrate low glycemic (LGI-G: ≥65% low glycemic carbohydrates daily; = 10) or high glycemic (HGI-G: ≥65% fat, ≤ 50 g carbohydrates daily; = 9) diet on fat and carbohydrate metabolism at rest and during exercise in 28 male athletes. Changes in metabolic parameters under resting conditions and during cycle ergometry (submaximal and with incremental workload) from pre- to post-intervention were determined by lactate diagnostics and measurements of the respiratory exchange ratio (RER). Additionally, body composition and perceptual responses to the diets [visual analog scale (VAS)] were measured. A significance level of α = 0.05 was considered. HFLC-G was associated with markedly decreased lactate concentrations during the submaximal (-0.553 ± 0.783 mmol/l, = 0.067) and incremental cycle test [-5.00 ± 5.71 (mmol/l) × min; = 0.030] and reduced RER values at rest (-0.058 ± 0.108; = 0.146) during the submaximal (-0.078 ± 0.046; = 0.001) and incremental cycle test (-1.64 ± 0.700 RER × minutes; < 0.001). In the HFLC-G, fat mass ( < 0.001) decreased. In LGI-G lactate, concentrations decreased in the incremental cycle test [-6.56 ± 6.65 (mmol/l) × min; = 0.012]. In the LGI-G, fat mass ( < 0.01) and VAS values decreased, indicating improved levels of gastrointestinal conditions and perception of effort during training. The main findings in the HGI-G were increased RER (0.047 ± 0.076; = 0.117) and lactate concentrations (0.170 ± 0.206 mmol/l, = 0.038) at rest. Although the impact on fat oxidation in the LGI-G was not as pronounced as following the HFLC diet, the adaptations in the LGI-G were consistent with an improved metabolic flexibility and additional benefits regarding exercise performance in male athletes.
摄入低血糖碳水化合物会增加肌肉脂肪利用率并保存肌糖原，这与耐力运动期间碳水化合物或脂肪代谢灵活性的提高有关。本试验的目的是研究4周高脂肪低碳水化合物饮食（HFLC-G：每天≥65%高血糖碳水化合物；n = 9）与高碳水化合物低血糖饮食（LGI-G：每天≥65%低血糖碳水化合物；n = 10）或高血糖饮食（HGI-G：每天≥65%脂肪，≤50克碳水化合物；n = 9）对28名男性运动员静息及运动时脂肪和碳水化合物代谢的影响。通过乳酸诊断和呼吸交换率（RER）测量来确定干预前后静息状态及周期测力计测试（次最大负荷和递增负荷）期间代谢参数的变化。此外，还测量了身体成分和对饮食的感知反应[视觉模拟评分法（VAS）]。显著性水平设定为α = 0.05。HFLC-G与次最大负荷期间（-0.553±0.783毫摩尔/升，P = 0.067）和递增周期测试期间显著降低的乳酸浓度[-5.00±5.71（毫摩尔/升）×分钟；P = 0.030]以及静息时降低的RER值（-0.058±0.108；P = 0.146）、次最大负荷期间（-0.078±0.046；P = 0.001）和递增周期测试期间（-1.64±0.700 RER×分钟；P < 0.001）相关。在HFLC-G组中，脂肪量减少（P < 0.001）。在LGI-G组中，递增周期测试期间乳酸浓度降低[-6.56±6.65（毫摩尔/升）×分钟；P = 0.012]。在LGI-G组中，脂肪量（P < 0.01）和VAS值降低，表明胃肠道状况改善以及训练期间用力感知增强。HGI-G组的主要发现是静息时RER增加（0.047±0.076；P = 0.117）和乳酸浓度增加（0.170±0.206毫摩尔/升，P = 0.038）。尽管LGI-G对脂肪氧化的影响不如HFLC饮食明显，但LGI-G组的适应性变化与男性运动员代谢灵活性的提高以及运动表现的额外益处一致。
