Chinese college students have demonstrated propensity toward physical inactivity. There is an imperative need for intervention on Chinese college students’ physical activity (PA) levels. An accurate
and objective assessment of PA level is therefore of particular importance for the purpose of developing and evaluating PA interventions. The Omron HJ-105 pedometer (OM) and the Polar Active activity
monitor (PAM) are widely used in school settings to assess PA levels, mainly for counting step. PAM is currently the only device that provides group solutions and allows account administrators to
access both individual and aggregated PA data. However, no research has been conducted on the accuracy of PAM in jogging or running conditions. OM was found to be an accurate step counter with
absolute percent error (APE) less than 5% in walking condition (2-4 mph). However, neither device has been validated amongst Chinese population. Thus, this study aimed to evaluate the accuracy of OM
and PAM among Chinese college students in a controlled setting.
A convenient sample of 28 Chinese college students participated in the study (Mage = 20.25, SD = 1.21) with 9 females and 19 males. Participants’ average BMI were within the normal range of Chinese
adults (BMIfemale = 19.3, BMImale = 22.55). All participants wore both OM and PAM and performed three trials for each condition (i.e., walking, jogging, and running). Before and upon completion of
each trial, participants were asked to record OM and PAM step count on a recording form. While performing a designated movement at participant’s own pace, they self-counted steps until reaching 100
Data analyses were performed in SPSS 21.0. Step count of a trial was calculated based on the difference between pre- and post trial reading. The step count APE was calculated using the formula of
(step counts-100)/100*100% and an absolute value was obtained. For each condition, one sample t-test was performed to compare the differences between OM or PAM step count and designated step count of
100. Dependent t-test was used to test the differences in average APE between OM and PAM.
Both devices significantly over-estimated steps in all conditions, except that PAM was relatively accurate in jogging condition. Except in walking condition, the average APEs of OM were under 5% and
were much smaller than APEs of OM (9.02% to 14.48%). OM showed significantly smaller average APE than PAM in jogging [t(27) = 3.01, p = .006] and running condition [t(27) = 4.46, p < .001].
Although OM over-estimated step counts in all conditions, it is a better step counter than PAM in jogging and running conditions for its lower average APEs. More repetition studies are needed to
confirm these findings, especially among other age groups or in a free-living setting. Future studies should also examine the internal consistency of both devices.