When D.C. students discovered last week that recess had been cut to a minimum of 15 minutes per day, many parents launched an immediate protest. Others merely shrugged.

“Teachers should be teaching. Students should be learning,” wrote Steve Sweeney, a parent at Tyler Elementary on Captiol Hill, whose three daughters told him that recess was no more than a chunk of unstructured social time in the middle of the day.

But research released this spring showed that recess — when it’s well-organized — can make a real difference in schools, resulting in students who feel safer, bully less and are more ready to learn.

The study, conducted by Mathematica Policy Research and Stanford University’s John W. Gardner Center for Youth and Their Communities, examined the approach to recess taken by Playworks, a national nonprofit that runs recess programs in low-income schools.

“Recess and other school-based playtime are some of the least studied elements of the school day,” says the study, funded by the Robert Wood Johnson Foundation.

“This new research contributes to a growing body of evidence that a safe, healthy, and organized recess environment—like the one Playworks provides—has the potential to be a key driver of better behavior and learning.”

This kind of recess is not a free-for-all. Playworks provides recess coaches, usually Americorps volunteers, who introduce and oversee games and activities that are meant to be vigorous, fun and inclusive. They teach kids to cheer each other on and to resolve their disputes amicably and fairly.

Playworks coaches are on duty in nearly two dozen cities, including the District, where they work in a dozen DCPS schools and two charters.

“We work to transform schools by transforming their recess,” said Susan Comfort, executive director of the organization's D.C. office, which opened in 2006.

Comfort said that Chancellor Kaya Henderson has been “incredibly supportive” of the organization and its approach, seeing it as an important ingredient for ensuring that students like school and want to attend.

See a list of the D.C. schools with Playworks coaches here and read the full Mathematica/Stanford study here.