Need Exercise? Pop a Pill (If You're a Mouse)

July 31, 2008 -- 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 reported Thursday that 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 Thursday 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.

Both drugs have been studied by researchers for other uses. The no-exercise drug is in advanced human testing 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 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, the researchers said.