Exercise and Wellness Program, School of Nutrition and Health Promotion, Arizona State University, Phoenix, AZ 85004, USA.
Int J Behav Nutr Phys Act. 2013 Apr 21;10:49. doi: 10.1186/1479-5868-10-49.
An evidence-based steps/day translation of U.S. federal guidelines for youth to engage in ≥60 minutes/day of moderate-to-vigorous physical activity (MVPA) would help health researchers, practitioners, and lay professionals charged with increasing youth's physical activity (PA). The purpose of this study was to determine the number of free-living steps/day (both raw and adjusted to a pedometer scale) that correctly classified children (6-11 years) and adolescents (12-17 years) as meeting the 60-minute MVPA guideline using the 2005-2006 National Health and Nutrition Examination Survey (NHANES) accelerometer data, and to evaluate the 12,000 steps/day recommendation recently adopted by the President's Challenge Physical Activity and Fitness Awards Program.
Analyses were conducted among children (n = 915) and adolescents (n = 1,302) in 2011 and 2012. Receiver Operating Characteristic (ROC) curve plots and classification statistics revealed candidate steps/day cut points that discriminated meeting/not meeting the MVPA threshold by age group, gender and different accelerometer activity cut points. The Evenson and two Freedson age-specific (3 and 4 METs) cut points were used to define minimum MVPA, and optimal steps/day were examined for raw steps and adjusted to a pedometer-scale to facilitate translation to lay populations.
For boys and girls (6-11 years) with ≥ 60 minutes/day of MVPA, a range of 11,500-13,500 uncensored steps/day for children was the optimal range that balanced classification errors. For adolescent boys and girls (12-17) with ≥60 minutes/day of MVPA, 11,500-14,000 uncensored steps/day was optimal. Translation to a pedometer-scaling reduced these minimum values by 2,500 step/day to 9,000 steps/day. Area under the curve was ≥84% in all analyses.
No single study has definitively identified a precise and unyielding steps/day value for youth. Considering the other evidence to date, we propose a reasonable 'rule of thumb' value of ≥ 11,500 accelerometer-determined steps/day for both children and adolescents (and both genders), accepting that more is better. For practical applications, 9,000 steps/day appears to be a more pedometer-friendly value.
将美国联邦指南中针对青少年的建议进行基于证据的翻译，即每天进行 60 分钟以上中等到剧烈强度的身体活动（MVPA），这将有助于健康研究人员、从业者和负责增加青少年身体活动（PA）的非专业人员。本研究的目的是确定自由活动步数/天（未经调整和经过计步器调整），以使用 2005-2006 年全国健康与营养调查（NHANES）加速度计数据正确分类儿童（6-11 岁）和青少年（12-17 岁）是否符合 60 分钟 MVPA 指南，并评估最近被总统挑战赛身体活动和健身奖计划采用的 12000 步/天建议。
在 2011 年和 2012 年对儿童（n=915）和青少年（n=1302）进行了分析。受试者工作特征（ROC）曲线和分类统计显示，候选步数/天切点可根据年龄组、性别和不同的加速度计活动切点区分是否达到 MVPA 阈值。使用 Evenson 和两种 Freedson 年龄特异性（3 和 4 METs）切点来定义最小 MVPA，并且针对未经调整和经过计步器调整的原始步数检查了最佳步数/天，以方便向非专业人员翻译。
对于每天有≥60 分钟 MVPA 的男孩和女孩（6-11 岁），儿童未经调整的 11500-13500 步/天范围是平衡分类错误的最佳范围。对于每天有≥60 分钟 MVPA 的青少年男孩和女孩（12-17 岁），未经调整的 11500-14000 步/天是最佳范围。转换为计步器刻度将这些最小值减少了 2500 步/天，降至 9000 步/天。所有分析的曲线下面积均≥84%。
没有单一的研究明确确定了青少年确切且不变的步数/天值。考虑到迄今为止的其他证据，我们提出了一个合理的“经验法则”值，即儿童和青少年（以及两性）每天≥11500 步，接受更多是更好的。对于实际应用，每天 9000 步似乎是一个更适合计步器的数值。
