Abstract：
The aim of the current study was to evaluate the effects of different levels of weightlifting training on bone mineral density (BMD) at different body sites (whole body (WB), lumbar spine (LS), femoral neck (FN), upper limbs (UL) and lower limbs (LL)) in a group of adolescents. Three groups of pubertal boys aged 13-15 years were recruited, including a control group (which included 13 untrained adolescents), a moderately trained group (which included 13 non-elite weightlifters, with four sessions of 2 hours per week) and a highly trained group (which included 13 elite weightlifters, with eight sessions of 2 hours per week). The three groups were paired for age and maturation index (using Tanner stages). Body composition, bone mineral content (BMC) and BMD were evaluated by dual-energy X ray absorptiometry (DXA). Physical performance variables (including weightlifting specific exercises, counter movement jump and squat jump) were measured using validated methods. Results showed that the values of BMD and physical performance variables were greater in the group of elite weightlifters compared to the group of non-elite weightlifters and the control group. In addition, the values of BMD and physical performance variables were higher in the group of the non-elite weightlifters compared to those of the control group. After adjusting for lean mass and squat jump, lumbar spine BMD, FN BMD, UL BMD and LL BMD remained significantly higher in the elite weightlifters\' group compared to the two other groups. In conclusion, the current study suggests that elite adolescent weightlifters have greater bone health parameters compared to moderately-trained adolescent weightlifters and untrained adolescents.
摘要：
本研究的目的是评估不同水平的举重训练对不同身体部位（全身（WB），腰椎(LS),股骨颈（FN），一组青少年的上肢（UL）和下肢（LL））。招募了三组13-15岁的青春期男孩，包括一个对照组（包括13个未经训练的青少年），一个受过中等训练的小组(包括13名非精英举重运动员，每周进行四次2小时的训练）和一个训练有素的小组（包括13名精英举重运动员，每周8个疗程2小时)。将三组进行年龄和成熟指数配对（使用Tanner阶段）。身体成分,通过双能X射线吸收法（DXA）评估骨矿物质含量（BMC）和BMD。身体表现变量(包括举重特定练习，反运动跳跃和下蹲跳跃)使用经过验证的方法进行测量。结果表明，与非精英举重运动员和对照组相比，精英举重运动员组的BMD和物理性能变量值更大。此外,与对照组相比，非精英举重运动员组的BMD和物理性能变量值更高。调整瘦体重和下蹲跳跃后，腰椎BMD,FNBMD,与其他两组相比，精英举重运动员组的ULBMD和LLBMD仍然明显更高。总之,目前的研究表明，与受过中等训练的青少年举重运动员和未经训练的青少年相比，优秀的青少年举重运动员的骨骼健康参数更高。
