Tennis: Careers Destroyed By Sport's Own Russian Roulette

Greg Rusedski claims that the mineral supplements and electrolytes he ingested had shown up negative for any banned substances, but there is widespread surprise that he took anything at all, given the level of awareness about supplements.

All professional tennis players are given a detailed list of banned substances and information on the dangers of nutritional supplements. There is even a 24-hour hotline available to them should they have any urgent inquiries.

Studies carried out by the International Olympic Committee and British sporting organisations have shown that such supplements are extremely dangerous for high-level athletes because many contain banned substances that can lead to positive tests.

Many sports bodies such as the British Olympic Association and UK Sport, which is responsible for testing British athletes, explicitly state that athletes should avoid supplements and that with a healthy and balanced diet there is no need to take them.

A survey carried out by the IOC in 2002 examined 634 nutritional supplements from around the world and found that almost 25% contained substances such as anabolic steroids that could lead to an athlete testing positive.

The survey also examined supplements on a country-by-country basis. Almost 20% of supplements in Britain were contaminated, 25% in Holland and 22% in Austria. A similar study carried out in the United States found that almost 20% of nutritional supplements contained banned substances.

The problem facing athletes and sports bodies is that the nutritional supplement industry is unregulated and is not subject to the same laws as the pharmaceutical industry.

Labels on nutritional supplements do not have to state their contents and there are no guarantees about purity, safety and effectiveness.

In some cases tests have revealed that nutritional supplements falsely claimed to contain certain substances, or that they included banned substances which were not listed. Another IOC survey found that almost 15% of nutritional supplements tested contained substances which were not listed on the labels but were banned in competitive sport.

No precise figures are available on how much the nutritional supplement industry is worth in Britain but in the US it is estimated to generate about $19bn (£10bn) each year.

There are estimated to be thousands of nutritional supplement products available to athletes in Britain either domestically or from the US.

After a number of studies, the IOC repeated its warning to athletes late last year not to use supplements and it demanded greater regulation of the industry.

Professor Ron Maughan, who is a member of the IOC nutrition group and is considered a world expert on nutritional supplements, said: "Various governments have ignored the issue of supplements for too long because we are talking about something that only affects a small amount of the population. Only athletes who are drug-tested have to worry about nutritional supplements and what is in them.

"It's difficult to put in legislation to deal with the supplements industry. Purity checks are very lax and many of the supplements are contaminated. The only way to tackle the problem is to use the laws that currently exist. Many supplements have substances that are subject to the medicines act and can only be issued with a prescription. Very rarely is action taken, however."

As Rusedski prepares his defence, the question being asked by many within the sporting world is why, given what is known or rather not known about nutritional supplements, do athletes continue to take them?

Professor Maughan, who is a visiting professor at the school of sport and exercise science at Loughborough University, said: "Athletes know full well about supplements and when they take them they know the risks they face. In many cases they decide to take the risk, in others they are badly advised by the people around them. Sometimes athletes are paid to take supplements because they are being endorsed by a particular company."

There is unlikely to be any regulation of the supplements industry in the near future, leaving many sports bodies to continue issuing warnings that athletes should avoid them.

A spokesman for UK Sport said: "Our advice is very clear and simple. Athletes should not take supplements because you can't trust what's in them. Athletes should avoid them at all costs and if they have balanced diets then there is no need to take them. Athletes must be responsible for what is in their bodies."

The key dates:

May 2, 2003 Czech player Bohdan Ulihrach is found guilty of a doping offence after metabolites of the steroid nandrolone are discovered in a routine drug test conducted on October 3, 2002 in Moscow. He is suspended for two years, fined $43,770 and deducted 100 ranking points.

Mid-May The Association of Tennis Professionals (ATP) learns that its own trainers are dispensing a supplement to players that may include nandrolone. Suspicions were raised after seven players tested positive for nandrolone in nine months, with a further 36 showing traces of the drug.

July 9 The seven otherwise unconnected male players, including Ulihrach, are exonerated despite positive tests, the latest in mid-May. The ATP admits its trainers unwittingly supplied the drug.

July 23 Greg Rusedski provides a urine sample at the RCA Championships in Indianapolis, after the defending champion had lost to Scott Draper in the second round.

January 6 2004 Argentina's Mariano Puerta is banned for nine months, fined and stripped of ranking points after testing positive for the anabolic steroid clenbuterol.

January 7 Rumours spread that Rusedski has tested positive. "I have never heard such a load of rubbish in my life," he says.

January 8 Rusedski admits to failing the test. "I fully expect to be found innocent."

February 9 The date scheduled for Rusedski's disciplinary hearing, to be held in Montreal.