The ingestion of quinine, a bitter tastant, improves short-term (30 s) cycling performance, but it is unclear whether this effect can be integrated into the last effort of a longer race. The purpose of this study was to determine whether midtrial quinine ingestion improves 3,000-m cycling time-trial (TT) performance. Following three familiarization TTs, 12 well-trained male cyclists (mean ± SD: mass = 76.6 ± 9.2 kg, maximal aerobic power = 390 ± 50 W, maximal oxygen uptake = 4.7 ± 0.6 L/min) performed four experimental 3,000-m TTs on consecutive days. This double-blind, crossover design study had four randomized and counterbalanced conditions: (a) Quinine 1 (25-ml solution, 2 mM of quinine); (b) Quinine 2, replicate of Quinine 1; (c) a 25-ml sweet-tasting no-carbohydrate solution (Placebo); and (d) 25 ml of water (Control) consumed at the 1,850-m point of the TT. The participants completed a series of perceptual scales at the start and completion of all TTs, and the power output was monitored continuously throughout all trials. The power output for the last 1,000 m for all four conditions was similar: mean ± SD: Quinine 1 = 360 ± 63 W, Quinine 2 = 367 ± 63 W, Placebo = 364 ± 64 W, and Control = 367 ± 58 W. There were also no differences in the 3,000-m TT power output between conditions. The small perceptual differences between trials at specific 150-m splits were not explained by quinine intake. Ingesting 2 mM of quinine during the last stage of a 3,000-m TT did not improve cycling performance.

奎宁是一种苦味剂，可以改善短期（30 秒）的骑行表现，但目前尚不清楚这种效果是否可以整合到更长距离比赛的最后努力中。本研究的目的是确定试验中摄入奎宁是否能提高 3,000 米自行车计时赛 (TT) 的表现。在三个熟悉 TT 之后，12 名训练有素的男性自行车手（平均值 ±  SD：质量 = 76.6 ± 9.2 kg，最大有氧功率 = 390 ± 50 W，最大摄氧量 = 4.7 ± 0.6 L/min) 连续几天进行了四次 3,000 米 TTs 实验。这项双盲交叉设计研究有四个随机和平衡条件： (a) 奎宁 1（25-ml 溶液，2 mM 奎宁）；(b) 奎宁 2，奎宁 1 的复制品；(c) 25 毫升甜味无碳水化合物溶液（安慰剂）；(d) 在 TT 的 1,850 米点消耗 25 毫升水（对照）。参与者在所有 TT 开始和结束时完成了一系列感知量表，并且在所有试验中持续监测功率输出。所有四种条件下最后 1,000 m 的功率输出相似：平均值 ±  SD：奎宁 1 = 360 ± 63 W，奎宁 2 = 367 ± 63 W，安慰剂 = 364 ± 64 W，对照 = 367 ± 58 W。条件之间的 3,000 米 TT 功率输出也没有差异。奎宁摄入量无法解释特定 150 米分段试验之间的细微感知差异。在 3,000 米 TT 的最后阶段摄入 2 mM 奎宁并没有改善循环性能。