Attention couch potatoes: exercise pill in the works

Exercise in pill form was unveiled Thursday - along with a warning that Olympians in Beijing could be tested for abusing the medications that transform mice into long-distance runners.

The drugs "genetically reprogram" muscle fibres mimicking many of the effects of exercise, say researchers who describe the impact on rodents as "stunning."

There is a good chance the drugs will work in humans and enable athletes to boost their endurance, says molecular biologist Ronald Evans, who heads the team at the Salk Institute in California. He also envisions the drugs giving couch potatoes a workout and helping bed-ridden individuals stay in shape.

Participants in a long-distance race run past the National Stadium in Beijing on April 30, 2008.Frederic J. Brown/AFP/Getty Images His team is reporting in the journal Cell that mice given the experimental medications ran up to a kilometre, or 68 per cent, farther than untreated mice.

The drugs, which are taken orally, are readily available from laboratory supply companies. While not approved for human use, there is concern some athletes may already be taking them to try to shave time off their races.

The World Anti-Doping Agency is aware of the possibility and has been working with Evans "to develop and implement ways to detect these molecules," says Frederic Donze, senior media relations manager for the Montreal-based agency that will check for a long-list of performance-enhancing drugs in Beijing.

The molecules, known as GW1516 and AICAR, mimic many of the physiological effects of exercise, says Evans, who describes them as "exercise pills" that trick muscles into "believing" and performing as if they have been working out.

In their research paper they describe how the drugs genetically reprogram muscle fibres to burn fat and contract repeatedly without fatigue.