Marijuana relaxes the nerves and puts the user in touch with the goddess Isis, sure, but is it performance-enhancing? There have been recent calls to reclassify marijuana as not a performance-enhancer.
This is a tough question for everyone. From an anti-drug perspective, if cannabis is performance-enhancing, then that contradicts a great deal of the propoganda on the subject; in the portrayal on public service announcements of the effects of THC, it is anything but performance-enhancing. It causes the user to sit around on the couch all day, only leaving once a day to pick up fast food, where he runs his car into a little girl on a bicycle on account of his diminished response time. In this view, marijuana's only role in sports is to weed out the abusers by giving them poor coordination and motivation. So it would seem to be in the best interest of marijuana's opponents to say that marijuana is not a performance-enhancer drug. But in doing so, they would be acknowledging that marijuana is basically innocuous.
For smokers, a 'Yes' means that they use a drug that is classified the same way as steroids, something most smokers would prefer not to be associated with. But a verdict of 'No', that marijuana is not a performance-enhancer, would reflect badly on smoking, as a habit. It would mean that any claim to deriving day-to-day benefit from marijuana smoking is delusional.
The truth is that marijuana has a complex range of effects, both positive and negative and both physical and mental. It depends on the strain of marijuana--indica and/or sativa and which subvariety--and on the user's own physiology, whether the herb will turn out to be performance-enhancing. The reason that marijuana is hard to classify like other drugs is that it is nothing like them.