School of Human Movement Studies, The University of Queensland, Brisbane, Queensland, Australia.
Med Sci Sports Exerc. 2013 Jun;45(6):1152-7. doi: 10.1249/MSS.0b013e3182808e23.
This study examined the influence of preexercise food intake on plasma pseudoephedrine (PSE) concentrations and subsequent high-intensity exercise. In addition, urinary PSE concentrations were measured under the same conditions and compared with the present threshold of the World Anti-Doping Agency (WADA).
Ten highly trained male cyclists and triathletes (age = 30.6 ± 6.6 yr, body mass [BM] = 72.9 ± 5.1 kg, and V˙O2max = 64.8 ± 4.5 mL·kg·min; mean ± SD) undertook four cycling time trials (TT), each requiring the completion of a set amount of work (7 kJ·kg BM) in the shortest possible time. Participants were randomized into a fed or nonfed condition and orally ingested 2.8 mg·kg BM of PSE or a placebo (PLA) 90 min before exercise; in the fed trials, they consumed a meal providing 1.5 g·kg BM of CHO. Venous blood was sampled at 30, 50, and 70 min and pre-warm-up and postexercise for the analysis of plasma PSE and catecholamine concentrations, and urine was also collected for the analysis of PSE concentration.
Independent of the preexercise meal, 2.8 mg·kg BM of PSE did not significantly improve cycling TT performance. The fed trials resulted in lower plasma PSE concentrations at all time points compared with the nonfed trials. Both plasma epinephrine and blood lactate concentrations were higher in the PSE compared with the PLA trials, and preexercise and postexercise urinary PSE concentrations were significantly higher than the threshold (150 μg·mL) used by WADA to determine illicit PSE use.
Irrespective of the preexercise meal, cycling TT performance of approximately 30 min was not improved after PSE supplementation. Furthermore, 2.8 mg·kg BM of PSE taken 90 min before exercise, with or without food, resulted in urinary PSE concentrations exceeding the present WADA threshold.
本研究考察了运动前食物摄入对血浆伪麻黄碱（PSE）浓度和随后高强度运动的影响。此外，在相同条件下测量了尿 PSE 浓度，并与世界反兴奋剂机构（WADA）目前的阈值进行了比较。
10 名训练有素的男性自行车运动员和三项全能运动员（年龄=30.6±6.6 岁，体重[BM]=72.9±5.1kg，最大摄氧量[V˙O2max]=64.8±4.5mL·kg·min；平均值±标准差）进行了 4 次自行车计时赛（TT），每次 TT 都要求在最短时间内完成一定量的工作（7kJ·kg BM）。参与者随机分为进食或不进食条件，并在运动前 90 分钟口服 2.8mg·kg BM 的 PSE 或安慰剂（PLA）；在进食试验中，他们摄入了一顿提供 1.5g·kg BM 的 CHO 的膳食。在 30、50 和 70 分钟以及热身前和运动后采集静脉血样，用于分析血浆 PSE 和儿茶酚胺浓度，同时采集尿液用于分析 PSE 浓度。
无论运动前是否进食，2.8mg·kg BM 的 PSE 均未显著改善自行车 TT 表现。与不进食试验相比，进食试验在所有时间点的血浆 PSE 浓度均较低。与 PLA 试验相比，PSE 试验中的血浆肾上腺素和血乳酸浓度均较高，且运动前和运动后的尿 PSE 浓度明显高于 WADA 用来确定非法 PSE 使用的阈值（150μg·mL）。
无论运动前是否进食，在补充 PSE 后，大约 30 分钟的自行车 TT 表现均未得到改善。此外，在运动前 90 分钟摄入 2.8mg·kg BM 的 PSE，无论是否进食，都会导致尿 PSE 浓度超过目前 WADA 的阈值。
