Genetically modified strength

Scientists may be on their way to developing a pill that could up strength and endurance.

We’ve all experienced that moment of exhaustion on the treadmill when we wished our legs would take us just a little farther, or hurt just a little less. New findings suggest that the dreaded plateau may be surmountable in the not-so-distant future.

Researchers at the Salk Institute for Biological Studies in La Jolla, California have created a breed of mice that are twice as strong and can run twice as far as normal mice. The study has the potential to result in drugs that would create the same souped-up abilities in humans.

The article, which appears in the November issue of the journal Cell, reports that scientists were able to breed the super-strong, high-endurance mice by suppressing the nuclear receptor corepressor 1 ("NCoR1"), a molecule that limits mammals' muscle growth. The study authors speculate that their findings could pave the way for drugs that would curb NCoR1 in humans, and experts speculate this would open the door to both legitimately useful therapy and abuse.

"On one end of the spectrum, this study will have the greatest potential impact on people who can’t exercise because they are ill or disabled," says Geralyn Coopersmith, exercise physiologist and director of the Equinox Fitness Training Institute, who says the study won't have much impact on the general population. "On the other end, it could interest elite athletes looking for that one little advantage to take them up a notch."

In terms of athletic advantage, it’s the long-distance competitors who stand to benefit. "This study saw that once the NCoR1 was taken out, there was an increase in muscles’ oxidative capacity — meaning the endurance increased," says Coopersmith. "That’s not so interesting for a sprinter, but very interesting for a marathoner."

Of course, any benefits seen for elite athletes would likely be the result of illicit use of these potential drug therapies. The drugs' legal use could be a significant help to those suffering from obesity, diabetes, age-related degeneration and other conditions that limit the power of their muscles. For Coopersmith, the hope is that those who are ill would use this newfound strength to get active again, as opposed to simply letting the drug allow them to continue a sedentary lifestyle.

"There’s so much more that exercise does for us," Coopersmith says. "Exercise keeps the heart functioning properly, and is important for a million other things, like our connective tissue and neurotransmitters. It influences every body function possible."