title: Influence of gender, BMI and Hispanic ethnicity on physical activity in children.
abstract: OBJECTIVE
  The purpose of this study was to examine the association between overweight status and physical activity (PA) among gender and ethnic (Hispanic vs. non-Hispanic) sub-groups in elementary school-age children.
  
  
  METHODS
  PA was assessed over five days using the Actigraph accelerometer in 169 fourth grade students (mean age 9.4 years; 50% female; 63% Hispanic; and 43% overweight, defined as body mass index, BMI > or = 85th percentile for age and gender) from four elementary schools in Los Angeles County, California.
  
  
  RESULTS
  In the total sample, boys and normal weight students had higher levels of total PA (counts per minute, cpm; p<0.05). Boys spent less time in sedentary PA (p=0.02) and more time in combined moderate to vigorous PA (MVPA, p=0.01). There was a significant gender, ethnicity, and overweight interaction for total PA and MVPA (both p<0.01). MVPA and counts per minute were significantly lower in overweight non-Hispanic girls and Hispanic boys (p<0.05) and marginally lower in overweight non-Hispanic boys (p=0.10) when compared with non-overweight students, while overweight Hispanic girls were more physically active than Hispanic non-overweight girls, though the difference was non-significant (p>0.05).
  
  
  CONCLUSIONS
  Data from the present study does not consistently support the prevailing hypothesis that overweight subjects engage in less PA. Results show overweight students engage in less PA than non-overweight students, with the exception that non-overweight Hispanic girls do not engage in more PA than their overweight peers. These results suggest the need for further investigation into the role that ethnicity and overweight status plays in PA levels, particularly among ethnic and gender sub-groups.
authors.affiliation: University of Southern California, Department of Preventive Medicine, Keck School of Medicine, & Institute for Prevention Research, Los Angeles, California 90033, USA.
authors.forename: Courtney
authors.initials: C
authors.lastname: Byrd-Williams
authors.forename: Louise A
authors.initials: LA
authors.lastname: Kelly
authors.forename: Jaimie N
authors.initials: JN
authors.lastname: Davis
authors.forename: Donna
authors.initials: D
authors.lastname: Spruijt-Metz
authors.forename: Michael I
authors.initials: MI
authors.lastname: Goran
mesh_terms: D015992:Body Mass Index; D002140:California; D002648:Child; D002675:Child, Preschool; D003710:Demography; D005006:Ethnicity; D015444:Exercise; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008019:Life Style; D008297:Male; D009043:Motor Activity; D050177:Overweight / Q000453:epidemiology; D012727:Sex Characteristics