High femoral bone mineral density accretion in prepubertal soccer players.
OBJECTIVE
To determine the effect of physical activity on bone mineral accrual during growth in prepuberal boys.


METHODS
Seventeen soccer players and 11 matched (physically active) control boys (Tanner 1-2, at the start of the study) were followed over a 3-yr period. Bone mineral content (BMC) and a real density (BMD) was measured by dual-energy x-ray absorptiometry. The maximal positive mechanical impulse (CJipos) and height jumped (Hj) during countermovement vertical jumps were assessed with a plate force. Additionally, 30-m running speed test (T30), 300-m run test (AC), and 20-m shuttle run test (MAP) were performed.


RESULTS
The soccer players attained better results in MAP and AC than the controls (P < 0.05). At the end of the follow-up, the controls increased their percentage of body fat in 11 units (P < 0.05) whereas it remained unchanged in the soccer players. Lean body mass increased with growth but more in the soccer players than in the controls (P < 0.05). The soccer players exhibited greater BMC in the legs and greater BMD in all bone-loaded regions at the end of the study (P < 0.05). During these 3 yr, the soccer players gained twice as much femoral neck and intertrochanteric BMC than the control group (P < 0.05) and increased their femoral neck BMD by 10% and their mean hip BMD by a third more than the control group (both P < 0.05). Multiple regression analysis showed that the improvement in T30 and CJipos has predictive value for the enhancement of bone mass in growing boys.


CONCLUSIONS
Long-term soccer participation, starting at a prepubertal age, results in greater improvement of physical fitness, greater acquisition of bone mass and a lower accumulation of body fat.
Vicente-Rodriguez
German
G
Department of Physical Education, University of Las Palmas de Gran Canaria, Spain.
Ara
Ignacio
I
Perez-Gomez
Jorge
J
Serrano-Sanchez
Jose A
JA
Dorado
Cecilia
C
Calbet
Jose A L
JA
D015502:Absorptiometry, Photon; D015308:Anaerobic Threshold / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D005080:Exercise Test; D005272:Femur Neck / Q000502:physiology; D006615:Hip / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000502:physiology; D008297:Male; D010012:Osteogenesis / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology; D011627:Puberty / Q000502:physiology*; D012044:Regression Analysis; D012420:Running / Q000502:physiology; D012916:Soccer / Q000502:physiology*; D013904:Thoracic Vertebrae / Q000502:physiology