The present randomized study investigated the effect of acute supplementation of 800 mg/kg of ketone monoester ingestion (KE) or placebo (PL) and 210 mg/kg of NaHCO3 co-ingestion on cycling performance of WorldTour cyclists during a road cycling stage simulation. Twenty-eight cyclists participated in the study (27.46 ± 4.32 years; 1.80 ± 0.06 m; 69.74 ± 6.36 kg). Performance, physiological, biochemical, and metabolism outcomes, gut discomfort, and effort perceived were assessed during a road cycling simulation composed of an 8-min time-trial (TT) performance + 30-s TT + 4.5 hr of outdoor cycling + a second 8-min TT + a second 30-s TT. Greater absolute and relative mean power during the first 8-min TT (F = 5.067, p = .033, ηp2=.163, F = 5.339, p = .029, ηp2=.170, respectively) was observed after KE than after PL (KE: 389 ± 34, PL: 378 ± 44 W, p = .002, d = 0.294 and KE: 5.60 ± 0.42, PL: 5.41 ± 0.44 W/kg, p = .001, d = 0.442). Additionally, greater concentration of β-hydroxybutyrate blood concentration (F = 42.195, p < .001, ηp2=.619) was observed after KE than after PL during the first steps of the stage (e.g., after warm-up KE: 1.223 ± 0.642, PL: 0.044 ± 0.058 mM, p < .001, d = 2.589), although the concentrations returned to near baseline after 4.5 hr of outdoor cycling. Moreover, higher values of anion gap were observed (F = 2.333, p = .026, ηp2=.080) after KE than after PL ingestion, after the warm-up and after the first 8-min and 30-s TT. Additionally, lower concentrations of HCO3- were reported in the KE condition after warm-up and after the first 8-min and 30-s TT. During the initial phase of the stage simulation, acute supplementation with KE + NaHCO3 co-ingestion enhanced 8-min TT cycling performance (3.1%) in WorldTour cyclists with a concomitant hyperketonaemia.

中文翻译：

---

酮单酯和碳酸氢盐共同摄入对世界巡回赛自行车运动员骑行表现的影响。

本随机研究调查了在公路自行车赛段模拟中，急性补充 800 mg/kg 酮单酯摄入量 (KE) 或安慰剂 (PL) 和 210 mg/kg NaHCO3 共同摄入量对世巡自行车运动员骑行表现的影响。28 名自行车手参与了这项研究（27.46 ± 4.32 岁；1.80 ± 0.06 m；69.74 ± 6.36 kg）。在公路自行车模拟中评估表现、生理、生化和代谢结果、肠道不适和感知的努力程度，该模拟由 8 分钟计时赛 (TT) 表现 + 30 秒 TT + 4.5 小时户外骑行 + 第二次计时赛组成8 分钟 TT + 第二个 30 秒 TT。与 KE 后相比，在第一个 8 分钟 TT 期间观察到的绝对和相对平均功率（分别为 F = 5.067，p = .033，ηp2=.163，F = 5.339，p = .029，ηp2=.170）更大PL（KE：389 ± 34，PL：378 ± 44 W，p = .002，d = 0.294 和 KE：5.60 ± 0.42，PL：5.41 ± 0.44 W/kg，p = .001，d = 0.442）。此外，在该阶段的第一步（例如，热身后 KE：1.223 ± 0.642，PL：0.044 ± 0.058 mM，p < .001，d = 2.589），尽管在户外骑行 4.5 小时后浓度恢复到接近基线。此外，KE 后观察到的阴离子间隙值高于 PL 摄入后、热身后以及第一个 8 分钟和 30 秒 TT 后的阴离子间隙值 (F = 2.333，p = .026，ηp2=.080)。此外，在预热后以及第一个 8 分钟和 30 秒 TT 后，KE 条件下的 HCO3- 浓度较低。在赛段模拟的初始阶段，同时摄入 KE + NaHCO3 的急性补充增强了伴有高酮血症的 WorldTour 自行车运动员的 8 分钟 TT 自行车表现 (3.1%)。