Major League Baseball officials have spoken of former Sen. George Mitchell's report on steroids as a way to put a stamp of understanding on the past and move toward a cleaner future.
But those who have battled doping for much longer in cycling, track and field, and other sports said that's wishful thinking. Hard experience has taught them that the economic and competitive drives behind doping inevitably lead athletes to newer, more effective, less detectable substances and methods.
"What we have to do is constantly look at the advances that are being made in medical science in a proper way and imagine how they might be abused by athletes," said David Howman, director general of the World Anti-Doping Agency.
Imagine if you wanted to run a marathon and could receive a simple shot that would tell your muscles to be better suited to endurance.
Or what if you tore your knee and an injection of your own stem cells not only helped it heal but also left the joint stronger than before?
These are not far-fetched scenarios reserved for science fiction but very real possibilities given the direction of medical research.
And that scares anti-doping officials at the highest levels of sports, who know that athletes will seize on any medical breakthrough to push their bodies to surreal heights.
"No matter what resources you put into enforcing the rules, there will be those who want to break them," Howman said. "If you're looking for a battle that is going to be won, this probably isn't it."
Even as professional leagues and law enforcement agents get better at catching steroid abusers, athletes have moved on to insulin and slightly altered versions of previously detectable designer steroids.
Eventually, scientists say, performance-enhancing substances might seem antiquated, left behind by genetic manipulation and medical procedures involving stem cells.
Human growth hormone is the first hurdle to clear. As the Mitchell Report made apparent, many athletes have turned to hGH for injury recovery or as a substitute for anabolic steroids (though scientists disagree over its effectiveness as a strength builder).
Baseball commissioner Bud Selig wants to convene an expert conference on hGH. Longtime drug researcher Don Catlin, who has received grants from Major League Baseball and the NFL to work on a reliable urine test for the substance, said he's making progress.
But by focusing too much on hGH, drug experts say, baseball officials could miss the reality that many athletes have already moved past it.
In the quest to keep up, WADA officials have spent five years courting the world's leading genetic scientists. Despite such efforts, Howman called improper use of genetics a "distinct threat."
"It's something that can and probably will happen, given athletes' tendency to push the envelope," said Dr. H. Lee Sweeney, a physiologist at the University of Pennsylvania.
The technology for gene therapy is evolving slowly, he said. Right now, researchers have to use viruses to get genetic alterations into the body. These injections trigger immune system responses that can be deadly. But the theoretical benefits of gene manipulation are staggering.
"You could change any property of the muscle," Sweeney said. "You could make it bigger, stronger, better for endurance. You could gear it to training so that you need a lot less effort to get the same effect. You could certainly extend the competitive life of the athlete."
Such manipulations might be undetectable without biopsy, he added.
By injecting adult stem cells into rats, Dr. Johnny Huard, a researcher at Children's Hospital of Pittsburgh, can speed and improve muscle healing. In some cases, the treated muscles end up stronger than they were pre-injury.
Recovery or strengthening?
The Mitchell Report and other sources have suggested that athletes turn to banned drugs as much to bounce back from injuries as to build strength. So it's not hard to imagine the appeal of Huard's methods.
Given that the patient would receive an injection of his or her own cells, detection would be difficult.
Some even theorize that by injecting stem cells into healthy muscle, athletes could replicate the growth and strengthening effects of steroids and human growth hormone. Such injections often have no effect in the lab, Huard said, but that doesn't mean no one will try.
Stem cells could be dangerous because they're similar to cancer cells. Huard doesn't have hard data but said he worries that patients who receive improper injections could face elevated cancer risks.
Perhaps his research will revolutionize the standard practices in sports medicine. Or perhaps outlaw doctors will try to use it to boost performance and, instead, hurt their patients.