There is a pill in front of you. It is a performance-enhancing drug, illegal, but undetectable. It will guarantee you success in your chosen field: whether that is as a writer, a film star, a banker, a musician, or a sportsman. It will make you be the best in the world at whatever it is you want to do. But there's a price. It is also guaranteed to kill you in five years. Are you prepared to take it?

This is the Goldman dilemma. Every two years from the mid-1980s to the mid-1990s researchers put that question to a group of elite athletes. The reward on offer was an Olympic gold medal. Invariably, around 50% of the athletes decided to take the pill. That statistic is often cited as proof of how unhinged athletes can become in the pursuit of success. But as the World Anti-Doping Agency is keen to stress, the research is now 15 years old. A team at the University of New South Wales in Canberra are updating the Goldman dilemma right now, rolling out a survey across team sports in Australia in an attempt to get a definitive and up-to-date answer.

They recently ran a small-scale version of the test in Canada. The number of competitors who would take the pill fell to just under 2%. It's possible that, as Wada would like us to believe, that drop is proof that their policies and propaganda are working. But there are a host of alternative explanations, and even the men who wrote the paper aren't fully convinced by that explanation. Jason Mazanov, an anti-doping scholar at UNSW, is part of the team working on the project. "It could be that athletes are more sensitive to answering the question," Mazanov says. When it comes to PED use "a code of silence is in place. Nobody has seen anything, nobody knows anything, and I think that is what the athletes are reflecting."

For Mazanov, that code of silence has expanded to encompass the culpable members of his own community. Athletes who dope, after all, do not supply themselves. Where a culture of PED use exists, a culture of team complicity often surrounds it. Last week, during a lecture he gave at a conference held by Sports Medicine Australia, Mazanov told his audience: "There are people in this room who are complicit in systemic doping in Australia." The response, he got, he says, was that "everyone looked at each other and said 'it's not me'. Well, the fact is that it has got to be someone here."

It is a doctor, Eufemiano Fuentes, who is at the heart of the Operation Puerto scandal unfolding in Spain. Across sports medicine and sports science, practitioners are increasingly being faced with the very same question that underpins the Goldman dilemma: "What are you prepared to sacrifice to succeed in sport?" Their principles are on one side of the balance, and their livelihoods on the other. According to Mazanov and several other sources inside the industry, the commercial pressures of modern sport are having a corrosive effect on medical ethics. "Sports medicine has become beholden to the performance process," Mazanov says.

"We are servants. We are contractors. We do what we are told instead of what we are supposed to do. Instead of acting in the best interests of the athlete, we are acting in the best interests of the sporting organisation." And the best and only interest of the modern sporting organisation, is winning, and by winning, turning a profit.

Doctors, Mazarov points out, are supposed to be moral guardians. Increasingly, though, "sports medicine and sports science has become so fascinated with just providing a service that improves short-term performance that we have not thought long and hard about whether what we are doing is right or conscionable". That sentiment is echoed by Dr Karim Khan, editor of the British Journal of Sports Medicine. "You have to be prepared to be sacked for your principles," Khan insists. "Once a doctor compromises his or her principles because they are scared of being sacked from a prestigious job, then they are making decisions on the wrong basis. And that's disastrous."

Consider this: top sports teams do not necessarily pay doctors to provide their medical cover. Increasingly, the reverse is true. Doctors pay to work for teams. Dr Khan explains that the prestige of having a top team as an employer is worth its weight in publicity to the private firms competing for the contracts. "I think a lot of people would assume a team would just try and choose the best medical support," Khan says. "But they have leveraged that prestige and turned it into part of their business model. Some clubs have started selling the rights to be the doctor to the team. If you were being kind, you would say they were also making sure those doctors were of the best quality."

Khan is concerned that "the tension is there between whether the doctor is working for the player, or the team, or the manager. Obviously medical ethics dictate that the doctor-patient relationship comes first. But if you are worried about getting sacked from a prestigious job, then that can be swayed."

That tension is there every time a doctor is pushed to get an injured player back on the field before they are fully fit. This is the crux of the PED problem. It's a curiously common misconception that athletes who play, for instance, tennis, cricket, or football, have less to gain from taking drugs because they can't improve your cover drive, or your backhand, or your passing.

"People don't understand how doping works," says James Connor, one of Mazanov's colleagues at UNSW. "You don't take the pill which means that you will be able to run faster, or jump further, you take the pill that means you can train harder for longer, and recover quicker."

"If an athlete isn't on the field," Mazanov says, "they lose their match fees, their appearance fees, and their sponsorship fees. So straight away there is this pressure coming on to the doctor from the athlete to make sure they get back on, because if they are not on, they are not earning at capacity." And that's before you factor in the player's fear of losing a place to a rival in the squad who plays in the same position, or the pressure applied by the manager whose job depends on the result and who wants their star player on the pitch.

"This is the consequence of the professionalisation and commercialisation of sport," Connor says. "I shudder to think of the pressures that some coaches put on their team doctors to make sure everyone is on the field and can play."

The public, Mazarov, says, tends to have a naive view of the realities of sport. "It is a bit like the fourth wall in TV. You don't break it by talking to the camera," he says. "We all want to say: 'Wow! That person ran really fast,' but we don't want to know about all the