Lohman Timothy G, Ring Kimberly, Schmitz Kathryn H, Treuth Margarita S, Loftin Mark, Yang Song, Sothern Melinda, Going Scott
Department of Physiology and Department of Nutritional Sciences, The University of Arizona, Tucson, AZ 85721, USA.
Med Sci Sports Exerc. 2006 Jun;38(6):1175-81. doi: 10.1249/01.mss.0000222846.27380.61.
To examine whether components of body composition (size, fat mass, and fat-free mass) were related to physical activity.
A random sample of 60 eligible sixth grade girls at each of 36 schools (six schools per region and six regions in total sample); complete measurements on 1,553 girls. Physical activity was assessed over 6 d in each girl using an accelerometer, and body composition was assessed using a multiple regression equation using body mass index and triceps skinfold. Minutes of moderate-to-vigorous and vigorous physical activity were estimated from accelerometer counts per 30 s above threshold values determined from a previous study.
Significant inverse relationships were found for all measures of body size and composition and all physical activity indices. The combination of fat and fat-free mass expressed as a weight and as an index (divided by height squared) along with race, SES, site, and school were most highly associated with physical activity in multiple regression analysis, accounting for 14-15% of the variance in physical activity. Fat mass was more closely related to moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) than fat-free mass with higher standardized regression coefficients.
We conclude that both fat mass or fat mass index as well as fat-free mass or fat-free mass index make independent contributions in association with physical activity levels. These indices are recommended for future studies.
研究身体成分的各个组成部分（体型、脂肪量和去脂体重）是否与身体活动相关。
从36所学校中随机抽取60名符合条件的六年级女生作为样本（每个地区6所学校，共6个地区）；对1553名女生进行全面测量。使用加速度计对每名女生进行为期6天的身体活动评估，并使用包含体重指数和肱三头肌皮褶厚度的多元回归方程评估身体成分。根据加速度计每30秒高于先前研究确定的阈值的计数估算中度至剧烈身体活动和剧烈身体活动的分钟数。
在身体大小和成分的所有测量指标与所有身体活动指标之间均发现了显著的负相关关系。在多元回归分析中，以体重和指数形式（除以身高平方）表示的脂肪和去脂体重与种族、社会经济地位、地点和学校相结合，与身体活动的相关性最高，占身体活动方差的14 - 15%。脂肪量与中度至剧烈身体活动（MVPA）和剧烈身体活动（VPA）的关系比去脂体重更密切，标准化回归系数更高。
我们得出结论，脂肪量或脂肪量指数以及去脂体重或去脂体重指数均与身体活动水平独立相关。建议在未来研究中使用这些指数。
