HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Free Full Text (PDF) Free All Versions of this Article: 105/2/734    most recent 00869.2007v1 Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Baxter-Jones, A. D. G. Articles by Bailey, D. A. Search for Related Content PubMed PubMed Citation Articles by Baxter-Jones, A. D. G. Articles by Bailey, D. A.

HIGHLIGHTED TOPIC
Biology of Physical Activity in Youth

The influence of physical activity on lean mass accrual during adolescence: a longitudinal analysis

¹College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; ²Department of Kinesiology, Michigan State University, East Lansing, Michigan; and ³School of Human Movement Studies, The University of Queensland, Brisbane, Queensland, Australia

Submitted 13 August 2007 ; accepted in final form 7 May 2008

During childhood, physical activity is likely the most important modifiable factor for the development of lean mass. However, the effects of normal growth and maturation must be controlled. To distinguish effects of physical activity from normal growth, longitudinal data are required. One hundred nine boys and one hundred thirteen girls, participating in the Saskatchewan Pediatric Bone Mineral Accrual Study, were repeatedly assessed for 6 yr. Age at entry was 8–15 yr. Stature, body mass, and physical activity were assessed biannually. Body composition was assessed annually by dual-energy X-ray absorptiometry. Physical activity was determined using the physical activity questionnaires for children and adolescence. Biological age was defined as years from age of peak height velocity. Data were analyzed using multilevel random-effects models. In boys, it was found that physical activity had a significant time-dependent effect on lean mass accrual of the total body (484.7 ± 157.1 g), arms (69.6 ± 27.2 g), legs (197.7 ± 60.5 g), and trunk (249.1 ± 91.4 g) (P < 0.05). Although the physical activity effects were similar in the girls (total body: 306.9 ± 96.6 g, arms: 31.4 ± 15.5 g, legs: 162.9 ± 40.0 g, and trunk: 119.6 ± 58.2 g; P < 0.05), boys for the same level of activity accrued, depending on the site, between 21 and 120% more absolute lean mass (g). In conclusion, habitual physical activity had a significant independent influence on the growth of lean body mass during adolescence, once biological maturity and stature were controlled.

growth and development; exercise; longitudinal studies

This article has been cited by other articles:

				T. G. Lohman Six-year longitudinal analysis shows physical activity impacts on lean mass development in adolescence J Appl Physiol, August 1, 2008; 105(2): 403 - 403. [Full Text] [PDF]