title: Pedometer-determined physical activity among youth in the Tokyo Metropolitan area: a cross-sectional study.
abstract: Providing large-scale descriptive data of objectively measured physical activity in youth is informative for practitioners, epidemiologists, and researchers. The purpose of this study was to present the pedometer-determined physical activity among Japanese youth using the Tokyo Metropolitan Survey of Physical Fitness, Physical Activity and Lifestyle 2011.
  
  
  
  This study used a school-based survey. The Tokyo Metropolitan Board of Education originally collected pedometer-determined steps per day in the fall of 2011. Data were collected from 15,471 youth aged 6 to 18 years living in Tokyo. Participants were asked to wear pedometers for 14 consecutive days, and daily steps logged in the final 7 days were selected for this analysis.
  
  
  
  At the primary and junior high school levels, boys (12,483 and 9476, respectively) had a significantly higher mean number of steps per day than did girls (10,053 and 8408, respectively). There was no significant difference in the mean number of steps per day between the sexes at the high school level. Mean steps per day decreased consistently with age and grade level; the lowest overall steps per day was observed in the last year of junior high school, although there was a slight increase in the subsequent year, the first year of high school.
  
  
  
  This study demonstrates a trend toward reduced physical activity with age in Japanese youth and a substantial difference in the number of steps per day between boys and girls in Tokyo. The age-related reduction in steps per day was greater in boys because they attained a higher peak value prior to this reduction, and sex-related differences in the step count disappeared in high school students.
authors: Department of Preventive Medicine and Public Health, Tokyo Medical University, 6-1-1 Shinjuku Shinjuku-ku, Tokyo, 160-8402, Japan.
authors: Noritoshi
authors: N
authors: Fukushima
authors: Department of Preventive Medicine and Public Health, Tokyo Medical University, 6-1-1 Shinjuku Shinjuku-ku, Tokyo, 160-8402, Japan. inoue@tokyo-med.ac.jp.
authors: Shigeru
authors: S
authors: Inoue
authors: Faculty of Engineering, Chiba Institute of Technology, 2-1-1 Shibazono, Narashino, Chiba, 275-0023, Japan.
authors: Yuki
authors: Y
authors: Hikihara
authors: Department of Preventive Medicine and Public Health, Tokyo Medical University, 6-1-1 Shinjuku Shinjuku-ku, Tokyo, 160-8402, Japan.
authors: Hiroyuki
authors: H
authors: Kikuchi
authors: Department of Preventive Medicine and Public Health, Tokyo Medical University, 6-1-1 Shinjuku Shinjuku-ku, Tokyo, 160-8402, Japan.
authors: Hiroki
authors: H
authors: Sato
authors: Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, 111 Totman Building University of Massachusetts Amherst 30 Eastman Lane, Amherst, MA, 01003-9258, USA.
authors: Catrine
authors: C
authors: Tudor-Locke
authors: Department of Nutritional Science, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, 1-23-1 Toyama, Shinjuku-ku, 162-8636, Tokyo, Japan.
authors: Shigeho
authors: S
authors: Tanaka
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D012111:Residence Characteristics; D012959:Socioeconomic Factors; D013334:Students / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D014041:Tokyo / Q000453:epidemiology; D016138:Walking / Q000706:statistics & numerical data*
keywords: Adolescents; Children; Cross-sectional study; Descriptive epidemiology; Steps; Survey