You probably have a vague sense that exercise is good for you—and you’ve probably heard that it’s “healthy for the heart.” But if you’re like most people, that’s not enough motivation to get you to break a sweat with any regularity. As I report in the TIME cover story, “The Exercise Cure,” only 20% of Americans get the recommended 150 minutes of strength and cardiovascular physical activity per week, more than half of all baby boomers report doing no exercise whatsoever, and 80.2 million Americans over age 6 are entirely inactive.
That’s bad news, but emerging evidence shows that there are plenty of compelling reasons to start moving at any age and even if you’re ill or pregnant. Indeed, scientists are learning that exercise is, indeed, medicine. “There is no pill that comes close to what exercise can do,” says Claude Bouchard, director of the human genomics laboratory at Pennington Biomedical Research Center in Louisiana. “And if there was one, it would be extremely expensive.”
You can read the whole story for more, but here are some of the amazing things that happen to a body in motion.
1. Exercise is great for your brain.
It’s linked to less depression, better memory and quicker learning. Studies also suggest that exercise is, as of now, the best way to prevent or delay the onset of Alzheimer’s disease, a major fear for many Americans.
Scientists don’t know exactly why exercise changes the structure and function of the brain, but it’s an area of active research. So far, they’ve found that exercise improves blood flow to the brain, feeding the growth of new blood vessels and even new brain cells, thanks to the protein BDNF (brain-derived neurotrophic factor). BDNF triggers the growth of new neurons and helps repair and protect brain cells from degeneration. It may also help people focus, according to recent research.
2. You might get happier.
Countless studies show that many types of exercise, from walking to cycling, make people feel better and can even relieve symptoms of depression. Exercise triggers the release of chemicals in the brain—serotonin, norepinephrine, endorphins, dopamine—that dull pain, lighten mood and relieve stress. “For years we focused almost exclusively on the physical benefits of exercise and really have ignored the psychological and emotional benefits of being regularly active,” says Cedric Bryant, chief science officer of the American Council on Exercise.