Physiological, Subjective and Performance Effects of Pseudoephedrine and Phenylpropanolamine During Endurance Running Exercise

Abstract

The aim of the study was to assess the effect of maximal therapeutic dosing of sympathomimetic amines found in over-the-counter (OTC) decongestant preparations on endurance running. Following familiarisation and a graded exercise test to determine maximal oxygen uptake (VO2 max), trained male runners (n = 8) completed four exercise sessions each separated by a minimum of one week. Each session was comprised of 20 min of sub-maximal treadmill running (70 % VO2 max) followed by a 5,000-m time trial on the treadmill under drug, placebo or control conditions. Drugs were administered in their commercial format over the 36-hour period prior to testing in the manufacturer's recommended maximal doses (i. e. 25 mg of phenylpropanolamine and 60 mg of pseudoephedrine four times daily). During sub-maximal endurance running no statistical differences were observed in heart rate, VO2, minute ventilation, respiratory exchange ratio, blood lactate, glucose or non-esterified fatty acids (NEFA) or ratings of perceived exertion with respect to the treatment administered. Similarly there were no statistical differences according to the condition during the 5,000-m running time trial, in terms of heart rate, ratings of perceived exertion, time of completion and pre and post exercise blood lactate, glucose or NEFA. The results indicate that in maximal, multiple therapeutic doses both pseudoephedrine or phenylpropanolamine as present in common OTC decongestant formulations do not affect, nor possess any ergogenic properties with regard to, endurance running.

Effect of a therapeutic dose of pseudoephedrine on swimmers’ performance

“…Of interest was the reduction in SBP in both tests with PSE use; an acute, but unexpected effect. This is contrary to a similar study by Chester et al, [4] which did not show a significant change in SBP or DBP during endurance running, even with use of a higher treatment dose of PSE (240 mg). Similarly, Hunter et al [16] reported no influence on performance in a cycling time trial with the use of 120 mg of PSE 2 hours prior to testing.…”

“…In our study, the greatest effect size was observed in DBP during the 50 m sprint, but the magnitude of this effect was almost certainly trivial (99%). The results of our study support that therapeutic PSE use does not convey quantifiable benefits during explosive anaerobic events, although the sporting discipline of our study differed from that of the aforementioned, which utilised either prolonged [16] or endurance [4] testing protocols. Likewise, enhancement of performance was not evident in endurance events in our study.…”

“…[2,3] These and other positive effects of PSE appeal to athletes, although doses ≥240 mg (above therapeutic doses) may be needed for a positive ergogenic effect. [4,5] Literature on the effectiveness of PSE as a performance enhancer is conflicting. Some studies have shown that PSE use improves 1 500 m running times, maximal torque in isometric knee extension, peak power during maximal cycling performance and lung-function capacity.…”

Hydration and Urinary Pseudoephedrine Levels After a Simulated Team Game

“…In these studies, PSE doses of 60-120 mg resulted in urine concentrations of 30-200 μg·ml -1 (Chester et al, 2003;Gillies et al, 1996), underscoring a wide individual variation in its metabolism and excretion. Alternatively, with doses of ≥180 mg, exercise performance may be enhanced during 30 s maximal cycling (Gill et al, 2000), 1,500-m track running (Hodges et al, 2006), and ~30 min cycling time-trials (Pritchard-Peschek et al, 2010).…”

“…Research investigating the influence of PSE on exercise performance suggests that any ergogenic effect does not manifest when taken in medicinal doses (≤120 mg) during submaximal and maximal running or during maximal strength activities (Chester et al,, 2003;Chu et al, 2002). In these studies, PSE doses of 60-120 mg resulted in urine concentrations of 30-200 μg·ml -1 (Chester et al, 2003;Gillies et al, 1996), underscoring a wide individual variation in its metabolism and excretion.…”