Sport Performance Research Institute New Zealand, AUT University, Auckland, New Zealand.
Int J Sport Nutr Exerc Metab. 2012 Jun;22(3):175-83. doi: 10.1123/ijsnem.22.3.175.
To determine the effects of ingesting caffeine (CAFF) and sodium bicarbonate (SB), taken individually and simultaneously, on 3-km cycling time-trial (TT) performance.
Ten well-trained cyclists, age 24.2 ± 5.4 yr, participated in this acute-treatment, double-blind, crossover study that involved four 3-km cycling TTs performed on separate days. Before each TT, participants ingested either 3 mg/kg body mass (BM) of CAFF, 0.3 g · kg⁻¹ · BM⁻¹ of SB, a combination of the two (CAFF+SB), or a placebo (PLAC). They completed each 3-km TT on a laboratory-based cycle ergometer, during which physiological, perceptual, and performance measurements were determined. For statistical analysis, the minimal worthwhile difference was considered ~1% based on previous research.
Pretrial pH and HCO₃ were higher in SB and CAFF+SB than in the CAFF and PLAC trials. Differences across treatments for perceived exertion and gastric discomfort were mostly unclear. Compared with PLAC, mean power output during the 3-km TT was higher in CAFF, SB, and CAFF+SB trials (2.4%, 2.6%, 2.7% respectively), resulting in faster performance times (-0.9, -1.2, -1.2% respectively). Effect sizes for all trials were small (0.21-0.24).
When ingested individually, both CAFF and SB enhance high-intensity cycling TT performance in trained cyclists. However, the ergogenic effect of these 2 popular supplements was not additive, bringing into question the efficacy of coingesting the 2 supplements before short-duration high-intensity exercise. In this study there were no negative effects of combining CAFF and SB, 2 relatively inexpensive and safe supplements.
确定单独和同时摄入咖啡因（CAFF）和碳酸氢钠（SB）对 3 公里计时赛（TT）表现的影响。
10 名训练有素的自行车运动员，年龄 24.2±5.4 岁，参与了这项急性治疗、双盲、交叉研究，涉及 4 天内进行的 4 次 3 公里自行车 TT。在每次 TT 之前，参与者分别摄入 3 毫克/千克体重（BM）的 CAFF、0.3 克/千克·BM-1 的 SB、两者的组合（CAFF+SB）或安慰剂（PLAC）。他们在实验室自行车测功计上完成了每次 3 公里 TT，在此期间确定了生理、感知和表现测量值。基于先前的研究，统计分析认为最小有意义差异约为 1%。
与 CAFF 和 PLAC 试验相比，SB 和 CAFF+SB 试验中的 SB 和 CAFF+SB 试验中的 pH 和 HCO₃ 更高。不同处理之间的感知用力和胃部不适的差异大多不明显。与 PLAC 相比，CAFF、SB 和 CAFF+SB 试验中的 3 公里 TT 平均功率输出更高（分别为 2.4%、2.6%和 2.7%），导致表现时间更快（分别为-0.9%、-1.2%和-1.2%）。所有试验的效应大小都较小（0.21-0.24）。
单独摄入时，CAFF 和 SB 均可提高训练有素的自行车运动员高强度自行车 TT 的表现。然而，这两种流行的补充剂的促效作用不是累加的，这使得在短时间高强度运动前同时摄入这两种补充剂的功效受到质疑。在这项研究中，同时摄入 CAFF 和 SB 这两种相对便宜且安全的补充剂没有副作用。
