Mice Marathon

While bulking up with steroids is a well-known practice among some athletes, a new drug developed to treat a metabolic disease has also given exercising mice the ability to run up to an hour longer, which is a lot in mouse time. "When we gave the mice a small amount of daily exercise in the presence or not of the drug, all showed an increased ability to run," said Ronald Evans, a researcher with the Salk Institute.

Once the mice had trained, Evans gave some of them the drug, known as GW1516, and discovered the drug mice kept on running. In what Evans called the "couch potato" experiment, the researchers also discovered that treating the mice with yet another drug gave even non-exercising mice greater endurance when they hit the track. "It's tricking the muscle into 'believing' it's been exercised daily," he said. "It proves you can have a pharmacologic equivalent to exercise." He noted that the drugs could be a boon to people who can't exercise due to health problems, but also have a "high potential for abuse" by athletes.