A natural experiment to assess recess frequency on children's physical activity in Arizona (U.S.) elementary schools.

Students attending elementary schools implementing 2 + recesses, in accordance with state policy, demonstrated greater MVPA and less sedentary time, providing preliminary evidence that recess frequency is associated with greater PA intensity among children during recess. Schools that adhere to state-level PA policies may provide a more supportive environment for PA, resulting in increased movement among students. Specifying recess frequency should be considered in statewide recess policy.