title: Objectively measured physical activity in urban alternative high school students.
abstract: BACKGROUND
  Alternative high school (AHS) students are an underserved population of youth at greater risk for poor health behaviors and outcomes. Little is known about their physical activity patterns.
  
  
  OBJECTIVE
  : The purpose of this study was to describe 1) physical activity levels of students attending alternative high schools (AHS) in St. Paul/Minneapolis, MN, and 2) compliance with wearing a physical activity accelerometer.
  
  
  METHODS
  Sixty-five students (59% male, 65% <18 yr old, 51% African American, 17% Caucasian, 32% mixed and other) wore an accelerometer during all waking hours for 7 d as part of the baseline assessment for a school-based physical activity and dietary behavior intervention. Accelerometer data were reduced to summary variables using a custom software program. Compliance with wearing the accelerometer was assessed by the number of days with >or=10 h of data. Accelerometer counts per minute and minutes spent in moderate-to-vigorous physical activity (MVPA) were calculated.
  
  
  RESULTS
  Students averaged 323 +/- 143.0 counts min(-1) and 51 +/- 25.5 min d(-1) of MVPA. Minutes of MVPA d(-1) were greater on weekdays compared with the weekend (52 +/- 27.3 vs 43 +/- 39.7 min d(-1), respectively; P = 0.05). However, students wore the accelerometer less on the weekends (weekdays = 17.2 +/- 3.0, weekend = 14.9 +/- 6.8 h d(-1)). Expressing minutes of MVPA as a percentage of the number of minutes of available data, students spent approximately 5% of their time in MVPA on weekdays and weekends. Forty-five percent of students had 7 d of data, 51% had 4-6 d, and 5% had fewer than 4 d. On average, students wore the accelerometer for 17 +/- 3.2 h d(-1) (range = 12.0-23.8 h d(-1)).
  
  
  CONCLUSIONS
  Compliance was high (95% of students provided at least 4 d of data), and physical activity was relatively low representing a vulnerable population in need of further study and intervention.
authors.affiliation: Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, USA. sirar001@umn.edu
authors.forename: John R
authors.initials: JR
authors.lastname: Sirard
authors.forename: Martha Y
authors.initials: MY
authors.lastname: Kubik
authors.forename: Jayne A
authors.initials: JA
authors.lastname: Fulkerson
authors.forename: Chrisa
authors.initials: C
authors.lastname: Arcan
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008910:Minnesota; D009043:Motor Activity; D013334:Students; D014505:Urban Population