Our aim is to analyse the eVect on bone mass of: (1) physical Wtness performance on a speciWc group of physical activity (PA) and, (2) PA on a speciWc physical Wtness performance group. Bone mineral content (BMC) by dual energy X-ray absorptiometry (DXA) and PA by accelerometers was assessed in 373 Spanish adolescents (182 males). Adolescents were classiWed as: active and nonactive (≥60 or 60 min day -1 of moderate-vigorous PA). Fitness was assessed through speed/agility, strength and cardiorespiratory tests. Adolescents were classiWed by tertiles (T1, T2 and T3). ANCOVA was used for the analysis with sex, height, lean mass, calcium intake and pubertal status as covariates. Adolescents with lower strength, speed/agility and cardiorespiratory Wtness (CRF) showed lower BMC in the whole body and extremities compared with adolescents with better results in these tests, mainly those non-active adolescents. Non-active adolescents with high Wtness levels showed higher BMC (whole body and upper limbs) than active ones. The conclusions included: (1) within the non-active group, lower levels of Wtness were associated with lower BMC; this might be through PA or trough an eVect of PA on muscle mass. (2) Non-active adolescents with high level of Wtness in most Wtness tests showed higher BMC than their active peers, in spite of their lower PA levels. These unexpected results could be inXuenced by several factors such as genetics, nutrition, type of exercise or sport, hormones and skeletal age.
- Bone health
- Fitness testing
- Physical activity recommendations
ASJC Scopus subject areas
- Orthopedics and Sports Medicine
- Public Health, Environmental and Occupational Health
- Physiology (medical)