Over-the-counter decongestants banned by the International Olympic Committee (IOC) appear to have no ergogenic effects – at least as far as endurance running performance is concerned.

That is the emphatic conclusion of a UK study, which examined the effects of two such preparations, given in maximal recommended therapeutic doses, on the performance of a small group of highly-trained male endurance runners.

The two drugs used in the study were pseudoephedrine, in the form of Boots Decongestant Tablets, and phenylpropanolamine, in the form of Mu-Cron. Both belong to a class of drugs known as ‘ephedrines’, which are banned in competition because of their similarity to amphetamines (not known as speed for nothing!).

The eight runners in the study completed four exercise sessions, each separated by at least a week. Each session consisted of 20 minutes of submaximal treadmill running (70% of vo2max), followed by a 5,000m time trial on the treadmill. The four sessions were completed under the following conditions:

• with pseudoephedrine;
• with phenylpropanolamine;
• with placebo (dummy drug);
• control (no drug).

Drugs were administered in their commercial format, in the manufacturers’ recommended maximal doses, over the 36-hour period prior to testing.

No statistical differences were observed between conditions across a range of measures, including heart rate, vo2, blood lactate, perceived exertion and time trial completion.

‘The results indicate,’ conclude the researchers, ‘that in maximal multiple therapeutic doses both pseudoephedrine and phenylpropanolamine, as present in common OTC decongestant formulations, do not affect, nor possess any ergogenic properties with regard to, endurance running.’

It is likely, they say, that any ergogenic properties these drugs possess may be evident only in higher doses, which are associated with hazardous side effects and would therefore be unethical to use in a trial.

However, on the evidence of this study, the researchers believe that a case could be made to legalise their use in therapeutic doses by increasing the currently allowable urine drug concentrations set by the IOC Medical Commission.

They acknowledge, however, that urine drug concentrations are extremely variable, being affected by diet, eating patterns and activity levels. ‘Further work is therefore required to establish the degree of variability in the [workings] of these drugs under different conditions.’

Int J Sports Med, 2003, 24:3-8

Isabel Walker

pseudoephedrine, phenylpropanolamine, ephedrines