CHEO Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
J Sports Sci. 2011 May;29(8):783-9. doi: 10.1080/02640414.2011.557744.
Accelerometry is increasingly used as a physical activity surveillance device that can quantify the amount of time spent moving at a range of intensities. This study proposes physical activity intensity cut-points for the Actical accelerometer. Thirty-eight volunteers completed a multi-stage treadmill protocol at 3, 5, and 8 km · h⁻¹ (2, 3.3, and 8 METs) while wearing Actical accelerometers initialized to collect data in 60-s epochs. Using a decision boundary analytical approach, moderate and vigorous physical activity intensity cut-points were derived for the Actical accelerometer. In adults (n = 26), the cut-point for moderate physical activity intensity occurred at 1535 counts per minute and the vigorous cut-point occurred at 3960 counts per minute. In children (n = 12), the cut-point for moderate physical activity intensity occurred at 1600 counts per minute and the vigorous cut-point occurred at 4760 counts per minute. Improved classification of physical activity intensity using the decision boundary cut-points was observed compared with using mean values for each protocol stage. The cut-points derived are recommended for use in adults. The cut-points derived for children confirm the findings of previous studies.
加速度计越来越多地被用作一种可以量化在不同强度下运动时间的身体活动监测设备。本研究提出了 Actical 加速度计的身体活动强度切点。38 名志愿者在佩戴 Actical 加速度计的情况下完成了一个多阶段跑步机方案，速度分别为 3、5 和 8 公里/小时（2、3.3 和 8 METs），加速度计初始设置为以 60 秒为一个时间单位收集数据。使用决策边界分析方法，为 Actical 加速度计推导了中高强度身体活动的切点。在成年人（n=26）中，中度身体活动强度的切点为 1535 计数/分钟，剧烈活动的切点为 3960 计数/分钟。在儿童（n=12）中，中度身体活动强度的切点为 1600 计数/分钟，剧烈活动的切点为 4760 计数/分钟。与使用每个方案阶段的平均值相比，使用决策边界切点可以更好地分类身体活动强度。建议在成年人中使用这些切点。为儿童推导的切点证实了之前研究的结果。
