Journal of Bone and Mineral Metabolism

, 26:366

Which element of physical activity is more important for determining bone growth in Japanese children and adolescents: the degree of impact, the period, the frequency, or the daily duration of physical activity?


    • Department of Public HealthKinki University School of Medicine
  • Yukihiro Ikeda
    • Department of Public HealthKinki University School of Medicine
  • Akemi Morita
    • Nutritional Education ProgramNational Institute of Health and Nutrition
  • Yuho Sato
    • Department of NutritionTenshi College
  • Hiroshi Naka
    • Department of Physical EducationKyoto University of Education
  • Masayuki Iki
    • Department of Public HealthKinki University School of Medicine
Original Article

DOI: 10.1007/s00774-007-0839-8

Cite this article as:
Tamaki, J., Ikeda, Y., Morita, A. et al. J Bone Miner Metab (2008) 26: 366. doi:10.1007/s00774-007-0839-8


This cross-sectional study examined the following four variables for impact on adolescent bone growth: the degree of impact, and the period, frequency, and daily duration of physical activity. We studied 127 boys and 136 girls between the ages of 12 and 15 years from northern Japan. Bone mineral density (BMD) at the spine and hip were measured using dual X-ray absorptiometry, and histories of participation in sports club activities beginning in first grade of elementary school were obtained through a questionnaire. The time spent participating in sports club activities between fourth and sixth grades during elementary school (E4-E6) was predictive of increased BMD, adjusted for height, weight, onset of pubic hair appearance, calcium intake, and grip strength, with the exception of hip BMD in females. Analysis of the period, frequency, daily duration of sports club activity, and a score of mechanical impact of physical activity (MECHPA) as substitute for time spent during E4–E6 revealed a significant relationship between the period of activity and BMD, with the exception of spine BMD in females. Activities performed two or more times a week during E4-E6 were also associated with an increased BMD at the hip for males and the spine region for females. Thus, the period and frequency of sports club activity, independent of its degree of impact or daily duration, in the age range of 9 to 12 years may be important for bone growth in children and adolescents.

Key words

bone mineral densitydual X-ray absorptiometryphysical activityJapanese adolescentsMECHPA
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© Springer Japan 2008