THE WORKOUT DRUG
Exercise is good for you. That’s hardly news: People who exercise tend to have longer, healthier lives. But until recently, researchers have tallied its benefits only in narrow slices: Exercise lowers your cholesterol and blood pressure; it keeps you from getting fat. Now it’s becoming clear that those known slices don’t add up to the full pie.
“When people totaled up those effects, they only account for about half the benefit,” says Michael Joyner, an exercise physiologist at the Mayo Clinic in Rochester, Minnesota. “So what’s contributing to the biomedical dark matter?”
To solve that mystery, researchers are now digging deeper into the mechanisms that underlie the benefits of physical activity. They are finding that exercise is both powerful and wide-reaching, affecting not just muscles and the cardiovascular system, but almost every part of the body, from the immune system to the brain to the energy systems within individual cells. And as scientists understand more precisely which levers exercise pulls to improve our health, clinicians are on the verge of being able to change their practice. The goal is to think of exercise as a medicine — a therapy that they can prescribe in specific doses for specific needs.
“It’s like your own personal regenerative
