Purpose: This study aimed to examine the presence and duration of reactivity to wearing a pedometer and recording daily step counts in free-living adults.
Methods: On the first visit to the laboratory, 90 participants (69% were females, age = 26.8 ± 13.0 yr, body mass index = 23.4 ± 4.0 kg·m−2), blinded to the study aim, were provided with a sealed pedometer (New Lifestyles NL-800) and informed that it was a “body posture monitor” (covert condition). Participants wore the pedometer throughout waking hours for 1 wk. On their return to the laboratory, stored step counts were recorded, and participants were informed that the device was a pedometer. Participants wore the pedometer unsealed (no restriction on viewing the step count display) for 2 wk, during which they recorded their daily step count in a diary (diary condition). Mean daily step counts recorded during the covert condition and during weeks 1 and 2 of the diary condition were compared using a repeated-measures ANOVA.
Results: There was a significant overall effect of study condition (P < 0.001), with post hoc analyses revealing that mean daily step counts reported during the first week of the diary condition (9898 ± 3002 steps per day) were significantly higher than those reported during the covert condition (8331 ± 3010 steps per day) and during the second week of the diary condition (8226 ± 3170 steps per day, P < 0.001).
Conclusions: Reactivity to wearing unsealed pedometers and step count recording seems to last for 1 wk. In the absence of any intervention material, step counts return to normal levels during the second week of monitoring and therefore represent a more accurate estimate of habitual activity. These findings have important implications to both researchers and practitioners interested in the use of pedometers for physical activity surveillance and promotion.
School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, UNITED KINGDOM
Address for correspondence: Stacy A. Clemes, Ph.D., School of Sport, Exercise and Health Sciences Loughborough University, Loughborough, Leicestershire, LE11 3TU, United Kingdom; E-mail: S.A.Clemes@lboro.ac.uk.
Submitted for publication September 2011.
Accepted for publication November 2011.