State law recommends recess.
California Education Code 33350 Educational Programs
(c) Encourage school districts offering instruction in kindergarten and any of grades 1 to 12, inclusive, to the extent that resources are available, to provide quality physical education that develops the knowledge, attitudes, skills, behavior, and motivation needed to be physically active and fit for life; to provide daily recess periods for elementary school pupils, featuring time for unstructured but supervised play; to provide extracurricular physical activity and fitness programs and physical activity and fitness clubs; and to encourage the use of school facilities for physical activity and fitness programs offered by the school, public park and recreation districts, or community–based organizations outside of school hours.
Local School Wellness Policy
This document addresses the frequency of recess in elementary schools.