ONE OF THE more contentious aspects of athletes consuming performance-enhancing substances is the issue of possible knock-on effects. In the US last summer, Mark McGwire's home-run odyssey captured the popular imagination. Yet the fact that a jar of androstenodione (not a banned substance in baseball, but banned by the IOC) was found in McGwire's (right) locker has caused ill-ease in some quarters, with various journalists all but requesting that the athlete publicly renounce the substance.

However, in England the opposite has just occurred. Abi Ekoku, the chairman of rugby league's professional players association, backed the defiant stance taken by the Bradford Bulls club, whose players use Creatine and Tribestan despite recommendations from the RFL that they should be avoided.

Although neither drug has yet been deemed dangerous enough for inclusion on the IOC's list of banned substances, there remains uncertainty about the potential longterm effects.

The Bradford Bulls' endorsement of creatine ties in with a sponsorship deal with America's General Nutrition Company. Matthew Elliot, the Bulls coach, said the supplements were purely beneficial - if used correctly.

"They reckon two pints of Guinness a day can be good. Twelve aren't - though they might feel pretty good at the time," he reasoned.