Beets Michael William, Morgan Charles F, Banda Jorge A, Bornstein Daniel, Byun Won, Mitchell Jonathan, Munselle Lance, Rooney Laura, Beighle Aaron, Erwin Heather
J Phys Act Health. 2011 Sep;8(s2):S295-S305. doi: 10.1123/jpah.8.s2.s295.
Pedometer step-frequency thresholds (120 steps·min, SPM) corresponding to moderate-to-vigorous intensity physical activity (MVPA) have been proposed for youth. Pedometers now have internal mechanisms to record time spent at or above a user-specified SPM. If pedometers provide comparable MVPA (P-MVPA) estimates to those from accelerometry, this would have broad application for research and the general public. The purpose of this study was to examine the convergent validity of P-MVPA to accelerometer-MVPA for youth.
Youth (N = 149, average 8.6 years, range 5 to 14 years, 60 girls) wore an accelerometer (5-sec epochs) and a pedometer for an average of 5.7 ± 0.8 hours·day. The following accelerometer cutpoints were used to compare P-MVPA: Treuth (TR), Mattocks (MT), Evenson (EV), Puyau (PU), and Freedson (FR) child equation. Comparisons between MVPA estimates were performed using Bland-Altman plots and paired t tests.
Overall, P-MVPA was 24.6 min ± 16.7 vs. TR 25.2 min ± 16.2, MT 18.8 min ± 13.3, EV 36.9 min ± 21.0, PU 22.7 min ± 15.1, and FR 50.4 min ± 25.5. Age-specific comparisons indicated for 10 to 14 year-olds MT, PU, and TR were not significantly different from P-MVPA; for the younger children (5-8 year- olds) P-MVPA consistently underestimated MVPA.
Pedometer-determined MVPA provided comparable estimates of MVPA for older children (10-14 year-olds). Additional work is required to establish age appropriate SPM thresholds for younger children.
已为青少年提出了与中等到剧烈强度身体活动（MVPA）相对应的计步器步频阈值（每分钟120步，SPM）。现在计步器具有内部机制来记录达到或高于用户指定SPM的时间。如果计步器提供的MVPA（P-MVPA）估计值与加速度计的估计值相当，这将在研究和普通公众中具有广泛应用。本研究的目的是检验青少年P-MVPA与加速度计-MVPA之间的收敛效度。
青少年（N = 149，平均8.6岁，范围5至14岁，60名女孩）佩戴加速度计（5秒时间段）和计步器，平均每天佩戴5.7±0.8小时。使用以下加速度计切点来比较P-MVPA：特鲁思（TR）、马托克斯（MT）、埃文森（EV）、皮尤（PU）和弗里德森（FR）儿童方程。使用布兰德-奥特曼图和配对t检验对MVPA估计值进行比较。
总体而言，P-MVPA为24.6分钟±16.7，而TR为25.2分钟±16.2，MT为18.8分钟±13.3，EV为36.9分钟±21.0，PU为22.7分钟±15.1，FR为50.4分钟±25.5。特定年龄组的比较表明，对于10至14岁的儿童，MT、PU和TR与P-MVPA没有显著差异；对于年龄较小的儿童（5至8岁），P-MVPA始终低估了MVPA。
计步器确定的MVPA为年龄较大的儿童（10至14岁）提供了相当的MVPA估计值。需要开展更多工作来为年龄较小的儿童确定适合其年龄的SPM阈值。
