Doping's next wave is already on us—and it could kill sport as we know it.

It is sport's doomsday scenario and haunts the Olympic ideal: a new generation of performance-enhancing drugs that can turn also-rans into gold medalists. Already, dozens if not hundreds of athletes, including undoubtedly some who are competing in Salt Lake City, have experimented with the rapidly emerging range of gene-altered drugs. Unfettered by fears of being caught they will, predict experts, shatter the accepted limits of human performance.

"I think genetic engineering may have already started," says former speed skating champion Johann Olav Koss, a member of the World Anti-Doping Agency (WADA). "We can't be naive. We must be realistic."

That may sound unnecessarily alarmist until one ponders the 30-year controversy surrounding Finnish cross-country skier Eero Mäentyranta. After winning two gold medals in the 1964 Winter Games and seven medals over three Olympics, he was dogged by accusations of blood doping—adding red blood cells to increase his oxygen and stamina. He agreed to a test, which showed he had far more blood cells than normal. But with no evidence of doping, the controversy morphed into a mystery.

With the recent rush of breakthroughs in genetic technology, scientists have unraveled Mäentyranta 's secret. Even more than the average elite athlete, he is a freak of nature. He carries a rare genetic mutation that churns out high amounts of the hormone erythropoietin (EPO), which makes the body produce ever more red cells, providing the boost to glide past competitors.

Mäentyranta's mutation is very rare, but anyone can enjoy this magic elixir. Since Amgen developed an injectable bio-engineered form of this hormone to treat severe anemia, EPO has become the drug of choice for endurance athletes.

It may be a decade away before doctors can remove embryonic fluid and generate a readout of the predicted sporting accomplishments of our prodigies-in-waiting, but synthetic drugs are already in use. A rich array of drugs are available or in the pipeline, including human growth hormone (HGH), which is used mostly by strength and speed athletes, and a concoction that would postpone sexual development to keep pre-adolescent female gymnasts and figure skaters in their performance prime. Scientists are also busy experimenting with gene therapies to regenerate the body after cartilage damage, tears and fractures.

The next giant step in the genetic revolution will come within the year, as geneticists begin experimenting with artificial genes that would self-regulate muscle growth with no fear of getting nabbed by doping cops.

"If direct injection is used, the DNA will only be present in that specific muscle," notes Peter Schjerling of the Copenhagen Muscle Research Center. "A positive test would require coring out actual muscle tissue. Not many athletes would allow that." Everyone from a struggling Blue Jay to a Kenyan-chasing Canadian distance runner could see their prospects brighten with an injection of the right genetic cocktail.

But there is a cost, and not just the potential disintegration of sport as we know it: EPO causes the blood to thicken, which has led to the death of more than 20 cyclists; HGH results in enlarged organs and uncontrollable bone growth in the face and hands; inserted genes could lead to problems only Dr. Frankenstein might imagine.

But, inevitably, scientists are working on this too. Stanford molecular pharmacologist Helen Blau has demonstrated that a gene could be introduced and then switched off with the use of an oral antibiotic. "An athlete could be genetically engineered to have a gene which increased their strength as they trained but then was shut off when required," Blau says. "It could be a future concern for the Olympics."

With these doomsday scenarios, it's not surprising many sport officials are calling for a ban. "Genetic manipulation is there to treat people who have ailments, not to treat a healthy person," IOC president Jacques Rogge said recently. "I am very clear on this."

But few scientists see the issue so starkly. There is a hazy and debatable line between "health restoration" and "performance enhancement." Imagine, for instance, an athlete using genetic modification to help overcome congenital asthma or some other genetic abnormality.

Even embryonic gene manipulation, which is further over the horizon, may not necessarily disqualify future athletes. As the Olympic 100-metre champion Maurice Greene has noted: "What if you're born with something having been done to you?"

Everyone agrees we are heading into uncharted waters. As WADA chairman Dick Pound recently said, "we will look back on Ben Johnson with his stanozolol [anabolic steroid scandal] and say 'that's like an ancient rock painting in a cave compared to what we face now with genetic engineering.'"