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˙O2max = 64.8 ± 4.5 mL·kg−1·min−1; mean ± SD) undertook four cycling time trials (TT), each requiring the completion of a set amount of work (7 kJ·kg−1 BM) in the shortest possible time. Participants were randomized into a fed or nonfed condition and orally ingested 2.8 mg·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·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·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 μg·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·kg−1 BM of PSE taken 90 min before exercise, with or without food, resulted in urinary PSE concentrations exceeding the present WADA threshold.
1School of Human Movement Studies, The University of Queensland, Brisbane, Queensland, AUSTRALIA; 2Athlete and Coach Support Services, Queensland Academy of Sport, Brisbane, Queensland, AUSTRALIA; 3The School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Queensland, AUSTRALIA; and 4School of Environmental and Life Sciences, The University of Newcastle, Ourimbah, New South Wales, AUSTRALIA
Address for correspondence: Kellie R. Pritchard-Peschek, PhD, School of Human Movement Studies, The University of Queensland, Brisbane, Queensland 4072, Australia; E-mail: firstname.lastname@example.org.
Submitted for publication August 2012.
Accepted for publication November 2012.