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?
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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 wordsbone mineral density dual X-ray absorptiometry physical activity Japanese adolescents MECHPA
- 3.Riis BJ, Hansen MA, Jensen AM, Overgaard K, Christiansen C (1996) Low bone mass and fast rate of bone loss at menopause: equal risk factors for future fracture: a 15-year follow-up study. Bone (NY) 19:9–12Google Scholar
- 5.Linden C, Ahlborg HG, Besjakov J, Gardsell P, Karlsson MK (2006) A school curriculum-based exercise program increases bone mineral accrual and bone size in prepubertal girls: two-year data from the Pediatric Osteoporosis Prevention (POP) Study. J Bone Miner Res 21:829–835PubMedCrossRefGoogle Scholar
- 6.Valdimarsson O, Linden C, Johnell O, Gardsell P, Karlsson MK (2006) Daily physical education in the school curriculum in prepubertal girls during 1 year is followed by an increase in bone mineral accrual and bone width: data from the prospective controlled Malmo pediatric osteoporosis prevention study. Calcif Tissue Int 78:65–71PubMedCrossRefGoogle Scholar
- 8.Bass S, Pearce G, Bradney M, Hendrich E, Delmas PD, Harding A, Seeman E (1998) Exercise before puberty may confer residual benefits in bone density in adulthood: studies in active prepubertal and retired female gymnasts. J Bone Miner Res 13:500–507Google Scholar
- 12.MacKelvie KJ, Petit MA, Khan KM, Beck TJ, McKay HA (2004) Bone mass and structure are enhanced following a 2-year randomized controlled trial of exercise in prepubertal boys. Bone (NY) 34:755–764Google Scholar
- 13.Hind K, Burrows M (2007) Weight-bearing exercise and bone mineral accrual in children and adolescents: a review of controlled trials. Bone (NY) 40:14–27Google Scholar
- 14.Naka H, Iki M, Morita A, Ikeda Y (2005) Effects of pubertal development, height, weight, and grip strength on the bone mineral density of the lumbar spine and hip in peripubertal Japanese children: Kyoto kids increase density in the skeleton study (Kyoto KIDS study). J Bone Miner Metab 23:463–469PubMedCrossRefGoogle Scholar
- 18.Kemper H, Twisk W, Mechelen W, Post G, Lips P (2000) A fifteen-year longitudinal study in young adults on the relation of physical activity and fitness with the development of the bone mass: the Amsterdam Growth and Health Longitudinal Study. Bone (NY) 27:847–853Google Scholar
- 19.Kemper H, Laura L, Hayman M, Mahon T (2002) Chapter 4: The importance of physical activity in childhood and adolescence. In: Health and Behavior in Childhood and Adolescence. Springer, New York, p 132Google Scholar
- 21.Hiroi M (1997) Report by the Subcommittee of Obesity and Sexual Function among Japanese Adolescent Girls in fiscal year 1995–1996: interrelationships, physique, menstrual cycle, change of body weight, and ideal body weight among Japanese adolescent girls, by way of a questionnaire (in Japanese). Acta Obstet Gynaecol Jpn 49:367–377Google Scholar