1. Body Composition as a Mediator between Cardiorespiratory Fitness and Bone Mass during Growth
- Author
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Luis M. Alegre, Irene Rodríguez-Gómez, Ignacio Ara, Amparo Gonzalez-Vergaz, Atilano Carcavilla, Beatriz Garcia-Cuartero, María Martín-García, and Angel Aragones
- Subjects
Male ,medicine.medical_specialty ,Adolescent ,Physical Therapy, Sports Therapy and Rehabilitation ,Incremental exercise ,Body Mass Index ,Mediator ,Bone Density ,Internal medicine ,medicine ,Sexual maturity ,Body Fat Distribution ,Humans ,Orthopedics and Sports Medicine ,Sexual Maturation ,Child ,business.industry ,Cardiorespiratory fitness ,Endocrinology ,Cardiorespiratory Fitness ,Prepubertal stage ,Lean body mass ,Female ,Densitometry ,business ,Body mass index - Abstract
Introduction and purpose To examine the effect of cardiorespiratory fitness (CRF) and muscle power output (MPO) on bone mass of prepubertal and pubertal children using lean mass (LM) and percentage of fat mass (%FM) as mediator variables. The hypothesis was that both LM and %FM would be independent mediators of the relationships during the sexual maturation period. Methods We analyzed 200 children (88 boys and 112 girls [11.5 ± 2.0 yr]). Body composition was analyzed by bone densitometry, and indirect calorimetry and cycle ergometer were used to calculate V˙O2peak (mL·kg·min) and MPO (W) during an incremental exercise test. Sample was divided by pubertal status. Results In the prepubertal group, LM and %FM acted independently as mediators in the relationship between bone mass and CRF or MPO (22%-25% for LM and 37%-50% for %FM, respectively). In pubertal children, LM acted as mediator at 37%. Conclusions Although the independent mediator role of LM and %FM in the associations between CRF or MPO and bone mass was present during the prepubertal stage, only LM remain its mediator role in these associations during the postpubertal period. Therefore, with growth and sexual maturation, the full effect of LM seems to increase, whereas the influence of %FM seems to disappear.
- Published
- 2020