Department of Society, Human Development, and Health, Harvard School of Public Health, Boston, MA 02115, USA.
Med Sci Sports Exerc. 2012 May;44(5):888-93. doi: 10.1249/MSS.0b013e31823fb254.
This study aimed to examine changes in physical activity among children and adolescents, by race/ethnicity, in the United States from 2003-2004 to 2005-2006.
Secondary analysis of the objectively measured accelerometer data among children and adolescents 6-19 yr: 2003-2004 (n = 1665) and 2005-2006 (n = 1716) from the nationally representative National Health and Nutrition Examination Survey 2003-2004 and 2005-2006. We estimated regression coefficients for change between the two periods by age group, accounting for sampling design and adjusting for age, sex, race/ethnicity, and number of hours monitored. We tested for differences in mean accelerometer counts per minute and minutes per day of moderate and vigorous physical activity trends by race/ethnicity and gender.
Physical activity decreased with age, boys were more active than girls, and non-Hispanic black children were more active than non-Hispanic whites (all P < 0.01). Overall mean accelerometer counts increased from 2003-2004 to 2005-2006 for children ages 6-11 yr (+31.6 counts per minute; 95% confidence interval = 0.51-62.6) but not among adolescents ages 12-19 yr. There was an increase over time in mean accelerometer counts among 6- to 11-yr-old non-Hispanic white children (+52.4 counts per minute, P = 0.007; 95% confidence interval = 15.7-89) but a decrease among non-Hispanic black and Mexican American children. No changes over the period in moderate and vigorous physical activity were found in either age group.
The lack of improvement in physical activity among all children and adolescents and a potentially emerging race-ethnic disparity indicate a need for further research on potential mechanisms underlying these differences. Effective interventions to improve physical activity opportunities and attenuate the decline in activity levels as children enter adolescence are needed.
本研究旨在考察美国儿童和青少年的身体活动在种族/民族方面的变化，研究对象为 6-19 岁的儿童和青少年，使用 2003-2004 年和 2005-2006 年全国代表性的国家健康和营养检查调查中的加速计数据进行二次分析。
对来自 2003-2004 年和 2005-2006 年全国健康和营养检查调查的 6-19 岁儿童和青少年的客观测量加速计数据进行二次分析（n=1665）和 2005-2006 年（n=1716）。我们根据年龄组估计了两个时期之间的变化回归系数，考虑了抽样设计，并根据年龄、性别、种族/民族和监测小时数进行了调整。我们测试了种族/民族和性别之间中高强度身体活动趋势的平均加速计每分钟计数和每天分钟数的差异。
身体活动随年龄增长而减少，男孩比女孩更活跃，非西班牙裔黑人儿童比非西班牙裔白人儿童更活跃（均 P<0.01）。总体而言，6-11 岁儿童的平均加速计计数从 2003-2004 年到 2005-2006 年增加（每分钟增加 31.6 次；95%置信区间为 0.51-62.6），但 12-19 岁青少年没有增加。6-11 岁非西班牙裔白人儿童的平均加速计计数随时间增加（每分钟增加 52.4 次，P=0.007；95%置信区间为 15.7-89），而非西班牙裔黑人和墨西哥裔美国儿童的平均加速计计数减少。在两个年龄组中，都没有发现中高强度身体活动在这期间有任何变化。
所有儿童和青少年的身体活动都没有改善，而且种族/民族之间可能出现新的差异，这表明需要进一步研究这些差异背后的潜在机制。需要采取有效的干预措施，增加身体活动机会，并减缓儿童进入青春期后活动水平的下降。
