Drug gives couch-potato mice benefits of workout

In this photo provided by the Salk Institute for Biological Studies, Ron Evans holds a vial of GW1516.

Here's a couch potato's dream: What if a drug could help you gain some of the benefits of exercise without working up a sweat?

Scientists report there is such a drug — if you happen to be a mouse.
Sedentary mice that took the drug for four weeks burned more calories and had less fat than untreated mice.
And when tested on a treadmill, they could run about 44 percent farther and 23 percent longer than untreated mice.
Just how well those results might translate to people is an open question.
But someday, researchers say, such a drug might help treat obesity, diabetes and people with medical conditions that keep them from exercising.

"We have exercise in a pill," said Ron Evans, an author of the study. "With no exercise, you can take a drug and chemically mimic it."

Evans, of the Salk Institute for Biological Studies in La Jolla, Calif., and the Howard Hughes Medical Institute, reports the work with colleagues in a paper published online by the journal Cell.
They also report that in mice that did exercise training, a second drug made their workout much more effective at boosting endurance.
After a month of taking that drug and exercising, mice could run 68 percent longer and 70 percent farther than other mice that exercised but didn't get the drug.
The no-exercise drug is in late-stage human testing by Kenilworth, N.J.-based Schering-Plough Corp. to see if it can prevent a complication of heart bypass surgery.

Evans noted the drugs might prove irresistible for professional athletes who seek an illegal edge. He said his team has developed detection tests for use by the World Anti-Doping Agency.
Evans said he has no financial interest in either the drug or the test.
Resveratrol, a substance being studied for anti-aging effects, has also been reported to enable mice to run farther before exhaustion without exercise training.
But the drugs in the new study appear to act more specifically on a process in muscles that boosts endurance, researchers said.
Still, it takes more than just altered muscles to turn a sedentary mouse into a distance runner, Evans said, and "honestly, I just don't know how that happens. Whether it would happen in a person, I don't know. I think it's a small miracle it happened at all."

The no-exercise drug is called AICAR. Previous experiments suggest that it might be useful for treating obesity, Evans said.
But it would have to be taken for a long time, he said, so its safety would have to be assured.
People who can't exercise because of a medical condition like joint pain or heart failure might also benefit from such a drug, experts said.

Eric Hoffman of the Children's National Medical Center in Washington, D.C., noted that AICAR mimics only aerobic exercise, not strength training that might be useful to the bedridden or elderly. He also said it's not clear whether the mouse results can be reproduced in people.