Do Adolescent Soccer Players Have Greater Skeletal Mineral Density Than Their Non-participant Peers?

Abstract

Acquisition of a high bone mass during adolescence is a key determinant of adult skeletal health. Although weight-bearing exercises are considered effective strategies for enhancing bone mineral status, relatively little is known about the influence of participation in soccer on bone mass of adolescents. PURPOSE: (1) to evaluate total and regional bone mineral density (BMD) in youth athletes participating regularly in a weight-bearing activity (soccer), and (2) to evaluate relationships between BMD and age, height, body mass, maturity status and soccer participation. METHODS: 151 adolescent boys participated in the cross-sectional study: 117 soccer players (SP) (13.7±1.5 years) and 34 non-athletes (NA) (13.3±1.3 years). SP were actively involved in the sport for at least 3 years (3-5 sessions/week, >300 min/week). NA participated only in the compulsory physical education classes at school (2 sessions/week, each 45-90 min) and did not participate in any kind of regular or organized sport activity for at least 3 years. Estimated maturity offset was used as an indicator of biological maturity status. BMD (g/cm2) of the whole-body, head, ribs, lumbar spine (L1-L4), pelvis, femoral neck, upper and lower limbs were assessed with dual-energy x-ray absorptiometry. Statistical procedures included unpaired t tests and multiple regression models. SPSS 18 was used in all analyses. RESULTS: (1) No significant differences were observed in age, height, body mass and estimated maturity offset between SP and NA. (2) Whole-body BMD was greater in SP compared to NA (1.04±0.14 vs. 0.96±0.11 g/cm2, p=0.001). (3) SP also had higher BMD (p<0.05) in the lumbar spine (9.8%), femoral neck (27.1%) and lower limbs (left 13.7%, right 12.6%). (4) BMD of the head, ribs, pelvis and upper limbs did not differ between the two groups. (5) Multiple regression analysis indicated that soccer participation and maturity status were positively associated with the whole-body (r2=67%), lumbar spine (r2=68%), femoral neck (r2=67%) and lower limbs (left r2=73%, right r2=59%) BMD. CONCLUSIONS: Adolescents SP have higher whole-body, lumbar spine, femoral neck and lower limbs BMD compared with NA. Regular participation in soccer has a positive effect on the bone mineral mass of adolescents, particularly in skeletal areas subjected to impact loading.