在控制条件下的跑步机上，时段长度对强度分类和测量准确性的影响：更好地理解加速度计测量。

Effect of epoch length on intensity classification and on accuracy of measurement under controlled conditions on treadmill: Towards a better understanding of accelerometer measurement.

机构信息

Universite de Pau & des Pays de l'Adour, e2s UPPA, MEPS, Tarbes, France.

出版信息

PLoS One. 2020 Jan 24;15(1):e0227740. doi: 10.1371/journal.pone.0227740. eCollection 2020.

DOI:10.1371/journal.pone.0227740

PMID:31978093

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6980633/

Abstract

PURPOSE

The aim of this study was to analyze the effect of epoch length on intensity classification during continuous and intermittent activities.

METHODS

Ten active students exercised under controlled conditions on a treadmill for four 5-min bouts by combining two effort intensities (running and walking) and two physical activity (PA) patterns (continuous or intermittent). The testing session was designed to generate a known level of moderate to vigorous PA (MVPA) for each condition. These PA levels were used as criterion measures to compare with the accelerometer measures. Data obtained from the accelerometer were reintegrated into 1-sec, 10-sec, 30-sec and 60-sec epochs. Equivalence testing was used to examine measurement agreements between MVPA values obtained with the different epochs and the reference values. Mean absolute percent errors (MAPE) were also calculated to provide an indicator of overall measurement error.

RESULTS

During the intermittent conditions, only the value obtained with the 1-sec epoch was significantly equivalent to the reference value. With longer epochs the difference increased for both intermittent conditions but in an opposite way: with longer epochs, MVPA decreased during walking but increased during running. Regarding the measurement accuracy, the pattern of variations according to the epoch length selected during the intermittent conditions was identical between walking and running: MAPE increased with the increase in epoch length. MAPE remained low only for the 1-sec epoch (7.6% and 2.7% for walking and running, respectively), increased at 31.3% and 34% for the 10-sec epoch and until near 100% with the 30- and 60-sec epoch lengths.

CONCLUSION

This study highlighted the misclassification of exercise intensity based on accelerometer measurement and described for the first time the extent and the direction of this misclassification. Moreover, we can confirm that the shorter epochs are more accurate to measure the real exercise intensity during intermittent PA whatever the intensity.

摘要

目的

本研究旨在分析时程长度对连续和间断活动中强度分类的影响。

方法

10 名活跃学生在跑步机上进行控制条件下的运动，通过将两种努力强度（跑步和步行）和两种体力活动（PA）模式（连续或间断）相结合，进行了四个 5 分钟的回合。测试方案旨在为每种条件生成已知水平的中等到剧烈体力活动（MVPA）。这些 PA 水平被用作与加速度计测量值进行比较的标准测量值。从加速度计获得的数据被重新整合为 1 秒、10 秒、30 秒和 60 秒的时程。等效性测试用于检查不同时程获得的 MVPA 值与参考值之间的测量一致性。还计算了平均绝对百分比误差（MAPE），以提供整体测量误差的指标。

结果

在间断条件下，只有 1 秒时程获得的值与参考值显著等效。随着时程的延长，两种间断条件下的差异都增加了，但方式相反：随着时程的延长，MVPA 在步行时降低，但在跑步时增加。关于测量精度，根据间断条件下选择的时程长度变化的模式在步行和跑步之间是相同的：MAPE 随着时程长度的增加而增加。只有 1 秒时程的 MAPE 保持较低（分别为步行和跑步的 7.6%和 2.7%），10 秒时程的 MAPE 增加到 31.3%和 34%，30 秒和 60 秒时程的 MAPE 接近 100%。