WHEN Heather Buch moved back to the United States from Denmark in 2005, she expected that school time for her son, Torben, would involve more work and less play. But as he attended kindergarten and first grade in Highland Park, she was surprised that other than time after lunch, there was hardly any outdoor play time during the school day.

“There’s almost no recess and all the emphasis is on academics,” Ms. Buch said. “It’s nothing like it was in Denmark or in my own childhood. Children need free play.”

She joins a growing legion of parents and educators who fear that recess is disappearing from the school schedule and needs to be rescued.