A large body of evidence suggests physical activity is inversely associated with several cardio-metabolic risk factors among children and adolescents. Despite these health benefits, a majority of youth are not meeting the physical activity guidelines set forth by the USDHHS. Schools have been identified as an ideal vehicle for interventions; however, research evidence indicates school-based interventions are not effective at increasing outside of school physical activity. Goal setting may be a potential effective strategy for increasing physical activity among youth; however no previous studies have examined the effects of goal setting on cardiorespiratory fitness and physical activity in middle school students. Therefore, the purpose of this study is to evaluate the effects of a S.M.A.R.T. goal setting and self-monitoring intervention on fitness and physical activity in middle school students. Two middle schools in Tallahassee, FL participated in this study. One school served as the intervention and the other served as a delayed intervention measurement only control. The students in the intervention school completed a one-time S.M.A.R.T. goal setting lesson. During the lesson, students were taught the definition of a goal, the importance of goal setting, and how to set S.M.A.R.T. goals. As part of the lesson, students completed a S.M.A.R.T. goal setting worksheet. The objectives of the worksheet activity were to teach students the concepts of S.M.A.R.T. goal setting and to apply this knowledge by creating personal fitness goals. Student fitness goals were entered into an interactive website that acted as a self-monitoring tool. Before and after the intervention, participating students completed a survey assessing student demographics, physical activity, and physical activity self-efficacy. Cardiorespiratory fitness levels, assessed by the PACER test, were also measured pre and post. Betweengroup differences in post-test scores, adjusted for baseline levels, were assessed for statistical significance using ANCOVA. Additional covariates included gender, race/ethnicity, grade level and weight status. After adjustment for baseline levels, students in the intervention school exhibited significantly higher PACER laps in comparison to the control school ((F[subscript (1,257)] = 58.0) p