The Center for Public Education says a review of federal data indicates one in 10 schools don't provide an average of 30 minutes a day of regularly scheduled recess, the South Florida Sun-Sentinel reported Monday.
The center found some school districts last year offered 144 minutes a week compared to 184 minutes five years earlier.
In Florida's Broward County, recess helps elementary schools meet a state requirement of 150 minutes of physical education a week.
But Broward Superintendent James Notter said a continuing focus on testing could lead local schools to make cuts if children need help with reading and math.
The federal No Child Left Behind act requires schools to ensure every child performs at grade level for reading and math by 2014.