Accuracy of pedometers and their use in a 10,000 steps per day intervention study

First, the accuracy and reliability of 10 electronic pedometers was assessed over the course of a 400-m walk. The Kenz Lifecorder (KZ), New Lifestyles NL-2000 (NL), and the Yamax Digi-Walker SW-701 (DW) were the most accurate in counting steps, displaying values that were within +/-3% of the actual steps taken, 95% of the time. The reliability within a single model (Chronbach's alpha) was >0.80 for all pedometers with the exception of the SL330. The intra-model reliability was exceptionally high (>0.99) in the KZ, OM. NL, and the DW.;Second, a comparison of 13 pedometer models was made over a 24-hour period. The criterion pedometer Yamax Digi-Walker SW-200 (YX200) was worn on the left side of the body and a comparison pedometer was worn on the right. The KZ, YX200, NL, Yamax Digi-Walker SW-701 (YX701), and SL330 yielded mean values that were not significantly different from the criterion. The Freestyle Pacer Pro (FR), Accusplit Alliance 1510 (AC), Yamax Skeletone CM-180 (SK), Colorado on the Move (CO), and Sportline 345 (SL345) significantly underestimated steps (P < 0.05) and the Walk4Life LS 2525 (WL), OM and Oregon Scientific PE316CA (OR) significantly overestimated steps (P < 0.05) when compared to the criterion.;Third, a comparison of the effects on body composition, cardiovascular risk factors and adherence was made in response to a 10,000 steps per day exercise prescription in sedentary, overweight males vs. females. Body weight, BMI, percent body fat, fat mass, fat-free mass, waist circumference, hip circumference, systolic blood pressure, diastolic blood pressure, and heart rate were determined at baseline, after 20 weeks and again after 36 weeks. A blood lipid profile was assessed at baseline and after 36 weeks. Men and women given a 10,000 steps per day exercise prescriptions experienced similarly significant improvements in body weight. BMI, percent body fat, fat mass, waist and hip circumferences, and HDL-C. When men and women were combined to explore the effect of adherence to the exercise prescription, the adherers significantly reduced body weight, BMI, percent body fat, fat mass, waist circumference, and hip circumference after 36 weeks while the non-adherers experienced little or no change in these variables.