We didn’t want to write about it. Seriously, we didn’t. Sure, Michael Phelps has digital technology, the 24-hour news cycle and precision blown glass to blame for his plight but we’re better than that.* But when US Swimming went and suspended Phelps for two months for, ultimately, acting his age, we felt compelled to write something. The 'Science' part of Popular Science restricts us from condemning the insanity of the punishment (note, however, they did nothing following his 2003 DUI). So below we offer an introductory, though hardly comprehensive, summary of marijuana and its (non)role as a performance-enhancing drug.

We should start by noting that US Swimming has made it quite clear that the ban of Phelps has nothing do with performance enhancement (not much to enhance) and everything to do with serving as the morality police.

“This is not a situation where any anti-doping rule was violated, but we decided to send a strong message to Michael because he disappointed so many people, particularly the hundreds of thousands of USA Swimming member kids who look up to him as a role model and a hero,” the Colorado Springs-based federation said in a statement.

But, that doesn’t stop us from asking why the drug is banned in sports in the first place. It’s a question English sports minister Richard Caborn , Spanish Athletics Federation President Jose Maria Odriozola and New Zealand Sports Drug Agency executive director Graeme Steel all asked several years ago. Caborn said the World Anti-Doping Agency should not be “in the business of policing society.” WADA’s science director, Dr. Olivier Rabin, added his thoughts during the discussion, “Our mandate is to fight doping in sport. We don’t go beyond that mandate and this has nothing to do with the social aspects of these drugs.”

According to WADA, prohibition of a substance is based on three questions: does it enhance performance, is it dangerous for the athlete, and is it against the ‘spirit of sport’? If the answer is yes to two of the questions, the substance is banned. Conceding that cannabinoids are dangerous to the athlete (smoke inhalation can never be good), the debate rests on performance enhancement and spirit of sport questions. Given Rabin’s comments we figured data must exist showing the power of pot in sports.

An oddity worth noting is that marijuana is only sometimes banned. During competition, athletes testing positive will suffer punishment but testing positive out of competition (during training) is okay. The rationale for this depends on whom you talk to. Some argue the ability of cannabinoids to calm nerves, thus enhancing performance, only works directly before a competition (unless you found some especially sticky stuff). Others argue it’s an example of WADA waffling on how marijuana aligns with the ‘spirit of sport’.

“In the case of marijuana, it’s a call by WADA to balance the strong views by many that it shouldn’t be on the list at all and say that their primary concern is limiting it during competition,” said Steel. “What athletes do during their own personal time is not WADA’s business. That’s my own personal opinion and not speaking officially on behalf of WADA.”

Cannabinoids are not the only substance on the ‘sometimes prohibited' list. Most stimulants with short-term effects, along with narcotics for pain relief, can be used freely outside of competition. These substances clearly can benefit performance; again, suggesting marijuana has similar capability.

So back to the core question. Can marijuana enhance performance? A cursory search of PubMed found a surprising lack of quality research on whether smoking a joint could help athletes win anything other than an eating contest. We doubt scientists would have a hard time recruiting volunteers so logic might suggest that most scientists just don’t buy for a second that inhaling Cheetos is a desirable side-effect for elite athletes. WADA provided several references for this piece that focused more generally on the pharmacology of marijuana but offered little data on actual physical performance.