Augmented trochanteric bone mineral density after modified physical education classes: a randomized school-based exercise intervention study in prepubescent and early pubescent children.
BACKGROUND
Of the few exercise intervention studies focusing on pediatric populations, none have confined the intervention to the scheduled physical education curriculum.


OBJECTIVE
To examine the effect of an 8-month school-based jumping program on the change in areal bone mineral density (aBMD), in grams per square centimeter, of healthy third- and fourth-grade children.


METHODS
Ten elementary schools were randomized to exercise (n = 63) and control groups (n = 81). Exercise groups did 10 tuck jumps 3 times weekly and incorporated jumping, hopping, and skipping into twice weekly physical education classes. Control groups did regular physical education classes. At baseline and after 8 months of intervention, we measured aBMD and lean and fat mass by dual-energy x-ray absorptiometry (Hologic QDR-4500). Calcium intake, physical activity, and maturity were estimated by questionnaire.


RESULTS
The exercise group showed significantly greater change in femoral trochanteric aBMD (4.4% vs 3.2%; P <.05). There were no group differences at other sites. Results were similar after controlling for covariates (baseline aBMD change in height, change in lean, calcium, physical activity, sex, and ethnicity) in hierarchical regression.


CONCLUSIONS
An easily implemented school-based jumping intervention augments aBMD at the trochanteric region in the prepubertal and early pubertal skeleton.
McKay
H A
HA
Departments of Human Kinetics, Medicine, Division of Endocrinology and Metabolism, and Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada.
Petit
M A
MA
Schutz
R W
RW
Prior
J C
JC
Barr
S I
SI
Khan
K M
KM
D015502:Absorptiometry, Photon; D001823:Body Composition; D001827:Body Height; D015519:Bone Density; D001846:Bone Development; D002648:Child; D015444:Exercise; D005260:Female; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D010806:Physical Education and Training