1. Purpose To examine the relationship among sleep duration, physical activity levels, and BMI of Caucasian and Hispanic middle school students. Research Question What is the relationship among sleep duration, step count, activity time, and BMI regardless of ethnicity, gender, or grade. Participants 227 7 th & 8 th grade students (108 boys, 119 girls) 60% Caucasian, 40% Hispanic Participants were from 3 Midwest School Districts Instrumentation Sleep duration was reported in hours via the School Sleep Habits Survey. Physical activity was determined through step count and activity time. Participants wore the Walk4Life Pro pedometer for four consecutive school days, which simultaneously recorded both step count and activity time. BMI was calculated using the Children’s BMI Tool for Schools. Introduction The prevalence of obesity among children and adolescents is increasing at an alarming rate. According to the National Health & Nutrition Examination Survey (2007-2008) it is estimated that 17% of children and adolescents (2-19 years) are obese. The accelerating rate of youth obesity in the United States indicates that this generation of children and adolescents will grow into the most overweight generation of adults in United States history (WHO, 2010). There is increasing epidemiological evidence suggesting a link between sleep duration, physical activity levels, and obesity among youth (Anderson & Whitaker, 2010). It has been reported that insufficient sleep is associated with higher levels of BMI in youth (Patel & Hu, 2008). Sleep, like physical activity and diet, plays an important role in the growth, maturation, and health of children and adolescents (National Sleep Foundation, 2010). Correlation Coefficients by Group Ronspies, S. 1, Madden, M. 2, Furtado, O. 1, White, G. 3 (1) Eastern Illinois University, (2) Pacific Lutheran University, (3) University of Arkansas at Little Rock Sleep Duration, Physical Activity, and BMI of Middle School Students American Alliance for Health, Physical Education, Recreation and Dance 2011 – San Diego Results  Overall means for daily step count, daily activity time, and sleep duration were 8,847 ± 3,777 steps, 91.53 ± 41.24 minutes, and 7.96 ± 0.98 hours respectively.  Correlation matrices are presented in tables by group with significant relationships noted (* = p <.01).  Pearson Correlation Coefficients indicated significant, strong relationships among sleep duration, step count, activity time, and BMI regardless of ethnicity, gender, or grade.  Relationships between sleep duration and both activity time and step count were slightly stronger in 7 th grade and Caucasian students. Discussion/Implications  The results present evidence that sleep duration is associated with physical activity levels in middle school students. It cannot be concluded, however that higher levels of physical activity are the result of additional sleep.  With physical activity and diet interventions showing mixed results, sleep duration may be a promising variable for both physical/health education and obesity prevention efforts to examine.