Good health is priceless. But with the total annual cost of health care in the U.S. topping $3 trillion a year (about $8,650 per capita), or roughly 18% of GDP, employers and insurance companies are always looking for ways to spend less on it.

A new study from the University of Michigan Health Management Research Center offers some encouraging news: Even as little as 10 or 20 minutes of daily exercise can “dramatically” lower the risk of developing serious chronic conditions like heart disease and diabetes, even for people at high risk.

The research project looked at how exercise affected 4,345 employees at a financial services company. About 30% of the employees were suffering from what doctors call metabolic syndrome, a cluster of risk factors (including high blood pressure and high cholesterol) that often leads to diabetes and heart disease. Overall, an estimated 34% of U.S. adults have metabolic syndrome.

The study found that, when the high-risk employees put in the 150 minutes per week of exercise recommended by the Centers for Disease Control, their health care costs dropped to the same level as those of healthy employees’. “It was a real surprise,” says Alyssa Schultz, a researcher who worked on the study.

Employees with metabolic syndrome who put in 30 minutes of exercise five times a week racked up an average of $2,770 in annual medical expenses, compared with $3,855 for at-risk employees who didn’t work out. The exercisers’ pharmacy costs alone fell by half.

But the biggest eye-opener from the study was how helpful it can be to exercise at all. The researchers noticed health-care cost savings even among people who reported just 10 minutes of vigorous movement per day.

Companies intent on cutting their health care bills might want to encourage employees to sit less and move more, Schultz says—and they needn’t do it through an elaborate wellness program. “With a little imagination, employers can come up with low-cost ways to get people moving at work, like putting up signs that remind employees to take the stairs instead of the elevator, or giving out maps of nearby walking routes that fit into a lunch hour.

“People tend to think that, if they can’t spare half an hour a day to spend on a treadmill at a gym, then they might as well not bother doing anything,” she adds. “But any number of minutes that is more than zero makes a noticeable difference.” Good to know.