In the war on drugs in sports, the drama of accusation and defense often captures the headlines.
But the fight also includes the small core of researchers and testing labs that face a scientific arms race in their efforts to keep drug tests abreast of new compounds that could give athletes an unfair competitive edge.
"It's been a cat and mouse game from the get-go," says Charles Yesalis, a professor of health policy at Penn State University in State College, Pa. Without a larger investment of time and effort, he says, an already difficult problem is likely to grow worse.
This week, two top US athletes are struggling to defend their reputations and titles from drug allegations.
Test results for US cyclist Floyd Landis, who won France's prestigious Tour de France last month, are expected by Saturday. The results will be the second of two tests on a fluid sample he was asked to provide following a stunning comeback on one of the race's most grueling stages. His stellar performance July 20 came on the heels of a poor showing during the previous day's stage.
According to The New York Times, which reportedly received its information from an unnamed source at the French lab testing the fluid, the first of two subsamples displayed a testosterone imbalance far higher than normal and that some of the hormone was synthetic.
Meanwhile, US sprinter Justin Gatlin faces a probe by the US Anti-Doping Agency (USADA), based in Colorado Springs, Colo., after testing positive for steroids. In acknowledging the test results last weekend, he argued that a disgruntled massage therapist used a testosterone cream on him without his knowledge. The therapist has denied the allegation.
Specialists note that the problem has grown in tandem with the rise of increasingly potent and specialized drugs for legitimate therapeutic use.
In the United States, the US Anti-Doping Agency has conducted between 4,700 and more than 7,000 tests annually since 2001. During the first half of this year, the agency has conducted some 4,500 tests for sports ranging from archery to paralympic table tennis.
In broad terms, the battle against using these drugs in sports dates back to the 1960s, notes Jim Stray-Gundersen, who has served as team physician to US and Norwegian Olympic teams and currently is an adjunct professor in the University of Utah's Department of Health. Initially, concerns centered on stimulants such as amphetamines, he explains.
"They were pretty straightforward to detect" via urine samples, he says.
But as athletes began to use anabolic steroids – synthetic derivatives of the naturally occurring male hormone testosterone – life for testers became more com- plicated. A urine sample can contain hundreds of types of naturally occurring steroids, researchers say. Assays not only have to detect the amount, but determine which are natural or synthetic. The more widespread steroid use has led to random testing even when athletes are not competing. Researchers are also working on better ways to test for blood doping – a practice that packs athletes with extra blood to supply more oxygen. Other experts are examining ways to detect genetic engineering, which has potential applications for sports abuse.
Current testing techniques are quite mature, notes Travis Tygart, the US Anti-Doping Agency's senior managing director. With a new research lab in Utah awaiting international certification and some high profile "gotchas" to the agency's credit, "the net is certainly tightening."
Others are not so sure. Penn State's Dr. Yesalis notes, for example, that you can only test for the steroid derivatives you know about. Unless someone comes forward with samples of a new variation, athletes can use it without getting caught.
One high-profile case involving the Bay Area Laboratory Co-Operative (BALCO) in Burlington, Calif., illustrates the point. Authorities had no idea that athletes were using a synthetic steroid known as THG, specifically designed to pass existing drug tests. A track coach alerted the USADA and shipped it a syringe containing some of the compound, Yesalis says. It took three months of lab work to identify the compound's molecular structure and develop a test for it.
Experts are eyeing a suspicious new entrant called IGF-1, a gene that carries the blueprint for a growth hormone. The IGF-1 compound is currently available for a limited number of serious, muscle-related problems, according to Gary Wadler, a physician and clinical associate professor of medicine at the New York University School of Medicine. Four years ago, researchers at the University of Pennsylvania published the results of experiments that introduced the gene into mouse muscles. The result was a "super mouse," which grew large muscles that showed very little deterioration with age.
After the university published its results, Dr. Wadler says, it was inundated with requests from coaches interested in using it on their athletes.
As a result of the publicity, Wadler says, "more people know about IGF-1 and doping than know about its therapeutic potential" for the elderly or people diagnosed with diseases such as muscular dystrophy. There is currently no doping test for IGF-1, he adds.
Despite the rise in testing labs and research efforts, anti-doping testing remains an underfunded, patchwork effort. Athletic authorities often rely on researchers who focus on a range of other topics as well, says Dr. Stray-Gundersen.
For anti-doping tests to become more effective, scientists need to be able to devote their full attention to the task, he says. The research will require a full study of archived fluid samples. In addition, authorities should create "grace limits" to better reflect the range of natural variations in individual hormone levels and the tests' inherent margins of error.