Resumen de Pseudoephedrine and Preexercise Feeding: Influence on Performance.
Kellie R. Pritchard-Peschek, David G. Jenkins, M. A. Osborne, Gary J. Slater, Dennis R. Taaffe
AB Purpose: 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). Methods: Ten highly trained male cyclists and triathletes (age = 30.6 +/- 6.6 yr, body mass [BM] = 72.9 +/- 5.1 kg, and V[spacing dot above]O2max = 64.8 +/- 4.5 mL[middle dot]kg-1[middle dot]min-1; mean +/- SD) undertook four cycling time trials (TT), each requiring the completion of a set amount of work (7 kJ[middle dot]kg-1 BM) in the shortest possible time. Participants were randomized into a fed or nonfed condition and orally ingested 2.8 mg[middle dot]kg-1 BM of PSE or a placebo (PLA) 90 min before exercise; in the fed trials, they consumed a meal providing 1.5 g[middle dot]kg-1 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. Results: Independent of the preexercise meal, 2.8 mg[middle dot]kg-1 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 [mu]g[middle dot]mL-1) used by WADA to determine illicit PSE use. Conclusion: Irrespective of the preexercise meal, cycling TT performance of approximately 30 min was not improved after PSE supplementation. Furthermore, 2.8 mg[middle dot]kg-1 BM of PSE taken 90 min before exercise, with or without food, resulted in urinary PSE concentrations exceeding the present WADA threshold
