Pedometer measures of free-living physical activity: comparison of 13 models.

PURPOSE: The purpose of this study was to compare the step values of multiple brands of pedometers over a 24-h period. The following 13 electronic pedometers were assessed in the study: Accusplit Alliance 1510 (AC), Freestyle Pacer Pro (FR), Colorado on the Move (CO), Kenz Lifecorder (KZ), New-Lifestyles NL-2000 (NL), Omron HJ-105 (OM), Oregon Scientific PE316CA (OR), Sportline 330 (SL330) and 345 (SL345), Walk4Life LS 2525 (WL), Yamax Skeletone EM-180 (SK), Yamax Digi-Walker SW-200 (YX200), and the Yamax Digi-Walker SW-701 (YX701).

METHODS: Ten males (39.5 +/- 16.6 yr, mean +/- SD) and 10 females (43.3 +/- 16.6 yr) ranging in BMI from 19.8 to 35.4 kg.m-2 wore two pedometers for a 24-h period. The criterion pedometer (YX200) was worn on the left side of the body, and a comparison pedometer was worn on the right. Steps counted by each device were recorded at the end of the day for each of the thirteen pedometers.

RESULTS: Subjects took an average of 9244 steps.d-1. The KZ, YX200, NL, YX701, and SL330 yielded mean values that were not significantly different from the criterion. The FR, AC, SK, CO, and SL345 significantly underestimated steps (P < 0.05) and the WL, OM, and OR significantly overestimated steps (P < 0.05) when compared with the criterion. In addition, some pedometers underestimated by 25% whereas others overestimated by 45%.

CONCLUSION: The KZ, YX200, NL, and YX701 appear to be suitable for most research purposes. Given the potential for pedometers in physical activity research, it is necessary that there be consistency across studies in the measurement of "steps per day."