School-based interventions are encouraged to support youth physical activity (PA). Classroom-based PA has been incorporated as one component of school wellness policies. The purpose of this pilot study is to examine the effects of integrating PA with mathematics content on math class and school day PA levels of elementary students. Participants include four teachers and 75 students. Five math classes are taught without PA integration (i.e., baseline) followed by 13 math classes that integrate PA. Students wear pedometers and accelerometers to track PA during math class and throughout the school day. Students perform significantly more PA on school days and in math classes during the intervention. In addition, students perform higher intensity (step min(-1)) PA during PA integration math classes compared with baseline math classes. Integrating PA into the classroom is an effective alternative approach to improving PA levels among youth and is an important component of school-based wellness policies.