Day M A, Dowthwaite J N, Rosenbaum P F, Roedel G G, Brocker A A, Scerpella T A
University of Wisconsin School of Medicine and Public Health, Madison, WI.
J Musculoskelet Neuronal Interact. 2015 Dec;15(4):341-9.
Youth exercise is associated with improved body composition, but details regarding timing and persistence are limited. We examined pre- and circum-menarcheal organized physical activity exposure (PA) as a factor in development of early post-menarcheal lean mass, fat mass and muscle strength.
Participants in a longitudinal study of musculoskeletal growth using dual energy X-ray absorptiometry (DXA) were included based on: 1) Whole body DXA scans: 0.5-1.5 years pre-menarche, 0.5-1.5 years post-menarche; 2) PA records for ⋝6 months preceding the first DXA (prePA) and for the inter-DXA interval (circumPA). Dominant arm grip strength and sit-ups tests coincided with DXA scans; PA, height and maturity were recorded semi-annually. Regressions correlated PA with lean mass/fat mass/strength, accounting for maturity, body size, and baseline values.
Seventy girls [baseline: 11.8 yrs (sd 1.0), follow-up: 13.9 years (sd 1.0)] demonstrated circum-menarcheal gains of 25-29% for lean and fat mass and 33% for grip strength. PREPA correlated with pre- and post-menarcheal lean mass, sit-ups and pre-menarcheal fat mass (p<0.05), but not grip strength. CIRCUMPA correlated with only post-menarcheal sub-head lean mass (p=0.03).
Lean mass and core strength at 1-year post-menarche were more strongly predicted by pre-menarcheal organized PA than by recent circum-menarcheal PA.
青少年运动与改善身体成分有关，但关于运动时间和持续性的详细信息有限。我们研究了月经初潮前和月经初潮前后有组织的体育活动暴露（PA）作为月经初潮后早期瘦体重、脂肪量和肌肉力量发展的一个因素。
纳入一项使用双能X线吸收法（DXA）进行肌肉骨骼生长纵向研究的参与者，依据如下：1）全身DXA扫描：月经初潮前0.5 - 1.5年，月经初潮后0.5 - 1.5年；2）第一次DXA扫描前≥6个月的PA记录（prePA）以及两次DXA扫描间隔期间的PA记录（circumPA）。优势手臂握力和仰卧起坐测试与DXA扫描同时进行；PA、身高和成熟度每半年记录一次。回归分析将PA与瘦体重/脂肪量/力量相关联，同时考虑成熟度、身体大小和基线值。
70名女孩[基线：11.8岁（标准差1.0），随访：13.9岁（标准差1.0）]显示月经初潮前后瘦体重和脂肪量增加25 - 29%，握力增加33%。PrePA与月经初潮前后的瘦体重、仰卧起坐以及月经初潮前的脂肪量相关（p<0.05），但与握力无关。CircumPA仅与月经初潮后头部以下瘦体重相关（p = 0.03）。
月经初潮后1年的瘦体重和核心力量，月经初潮前有组织的PA比近期月经初潮前后的PA预测性更强。
