Research Report. Number of Pedometer-Assessed Steps Taken Per Day by Adults: A Descriptive Meta-Analysis. Background and Purpose. Methods.

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1 Research Report Number of Pedometer-Assessed Steps Taken Per Day by Adults: A Descriptive Meta-Analysis Richard W Bohannon RW Bohannon, PT, EdD, DPT, NCS, FAPTA, FAHA, is Professor, Department of Physical Therapy, Neag School of Education, University of Connecticut, 358 Mansfield Rd, Storrs, CT (USA). Address all correspondence to Dr Bohannon at: richard.bohannon@ uconn.edu. [Bohannon RW. Number of pedometer-assessed steps taken per day by adults: a descriptive meta-analysis. Phys Ther. 2007; 87: ] 2007 American Physical Therapy Association Background and Purpose Although a criterion reference of 10,000 steps per day is recommended for health benefits, a literature search yielded no normative standard for daily steps. Therefore, a meta-analysis was used to estimate the number of pedometer-documented steps that adults take daily. Methods Studies were retrieved using electronic databases and cross-referencing from retrieved studies. A random-effects model and 95% confidence intervals (CIs) were used for all analyses of daily step data. Results Seventy-one outcomes, representing 6,199 subjects from 42 studies, met the inclusion criteria. Excluding Amish subjects, the daily step count averaged 9,448 (95% CI 8,899 9,996) and was greater in subjects younger than 65 years of age (mean 9,797, 95% CI 9,216 10,377) compared with subjects 65 years of age or older (mean 6,565, 95% CI 4,897 8,233). Discussion and Conclusion This study provides an estimate of the number of daily steps taken by adults. The number is less than the recommended 10,000 steps per day and is especially low in adults 65 years of age or older. Post a Rapid Response or find The Bottom Line: f Physical Therapy Volume 87 Number 12 December 2007

2 The benefits of physical activity are many and well-established. Although there are numerous modes of aerobic physical activity in which individuals can engage, walking is the most widely practiced aerobic physical activity in the United States. 1 Of 1,816 adult respondents to the US Physical Activity Study, Eyler et al 2 noted that 34% walked regularly (ie, 5 days per week for at least 30 minutes) and 46% walked occasionally (ie, not regularly but 10 minutes per session). Among elderly people, walking may be particularly preferred as a mode of exercise. 3,4 With the advent of pedometers, it has become economically feasible to accurately quantify the number of walking steps that individuals actually take on a daily basis in a realworld setting. Currently, 10,000 steps per day is widely promoted as a target for achieving health-related benefits. 5 Individuals who meet the goal are more likely to meet the current activity guideline of an accumulated 30 minutes of moderate physical activity on most, if not all, days per week. 6 The goal of 10,000 steps is supported by Iwane et al, 7 who found that walking 10,000 steps was effective for lowering blood pressure and increasing exercise capacity in patients with hypertension, and by Schneider et al, who demonstrated that a 10,000 step per day exercise prescription resulted in weight loss over 36 weeks in previously sedentary, overweight/obese adults. 8(p85) The usefulness of a criterion reference of 10,000 steps per day notwithstanding, its comparability to actual walking volume is not known. Moreover, it does not provide a standard by which an individual s behavior can be compared with that of his or her peers. For such comparisons, normative reference values are required. 9 Since the commercial introduction of pedometers in the 1980s, many studies have been published that describe walking activity on the basis of the number of steps taken per day by individuals who apparently are healthy. However, the mean or median number of steps taken per day varies widely (Tab. 1) Given the variability found in these studies, a need exists to consolidate available information to provide an estimate of the number of steps taken per day by adults and to examine whether estimates vary among subgroups. Although I am aware of one review of the literature on this topic, the review involved a traditional, narrative approach. 52 Meta-analysis is an alternative approach in which individual studies addressing a common issue are statistically combined to arrive at a conclusion about the body of research. 53,54 Meta-analysis provides the opportunity to: (1) increase power for primary outcomes and subgroup analysis, (2) help resolve uncertainty when studies disagree, (3) improve estimates of treatment effectiveness, and (4) answer questions not posed at the start of individual trials. 54 Thus, considering the potential health relevance of quantifying the steps taken per day by adults, the variability in the literature regarding the number of daily steps taken by adults, and the absence of meta-analytic work summarizing the number of daily steps by adults, the purpose of this study was to use a meta-analytic approach to summarize the number of steps taken per day by adults. Method Literature Search Potentially relevant studies were identified via electronic searches of MEDLINE, CINAHL, EMBASE, Science Citation Index, and PsycINFO. The key words pedometer and pedometry were used in the searches. To capture studies published prior to January 2005, the last search was conducted in February The reference lists of all retrieved studies were examined to locate other potentially relevant articles not identified by the database searches. Thereafter, I asked experts on the topic (Catrine Tudor-Locke and David R Bassett) to review the reference list for omissions. Study Selection and Data Retrieval Studies were included in the metaanalysis if they met the following criteria: (1) were published prior to January 2005; (2) included adult humans, aged 18 years and older, who apparently were healthy; (3) were disseminated in English-language journals; and (4) reported data (mean and standard deviation) for the number of steps taken as assessed by a pedometer. I selected all studies included in the meta-analysis. Studies were excluded if they: (1) involved children, (2) were limited to patients or individuals with pathologies or abnormalities (eg, hypertension, obesity), or (3) contained no relevant data. Studies published in a foreign language were not included because of concern about the translation and interpretation of findings. Data Abstraction A coding sheet was developed that could hold information on: (1) study characteristics (eg, year of publication), (2) subject characteristics (eg, age, sex), (3) pedometer assessment characteristics (eg, make and model of pedometer), and (4) the primary outcome (number of steps taken per day). For intervention studies that described the number of steps taken at multiple time points (eg, baseline, final), only baseline data were used. For studies involving both patients and matched nonpatients, only data from the nonpatients were used. In cases where authors published multiple articles and the data were de- December 2007 Volume 87 Number 12 Physical Therapy f 1643

3 termined to not be from unique samples, redundant data were excluded. If the uniqueness of subjects could not be determined across studies, the authors were contacted to clarify such. Such a contact resulted in the exclusion of one study. Sample sizes, means, and dispersion statistics (eg, standard deviations) were abstracted for each outcome from each study. In cases where step data (mean and standard deviation) were not provided or could not be estimated from the information provided in the study, contact with the authors was attempted to obtain the data. Authors of 2 articles could not be reached, authors of 1 article were contacted but did not provide information, and authors of 1 article provided information. I abstracted and coded all retrieved studies. In addition, an assistant independently abstracted and coded the data from the studies. Our results were compared, and discrepancies were reconciled. Data Analysis Pooled outcomes (mean and 95% confidence intervals [CIs] for steps per day) were calculated by assigning weights equal to the inverse of the variance for the number of steps taken per day. A random-effects model that controls statistically for heterogeneity was used to pool results. 53 However, I also examined for heterogeneity based on a fixedeffects model using the Q statistic. 53 Because the Q statistic suffers from low power, the alpha level for statistically significant heterogeneity was set at P.10 versus P In order to examine the sensitivity of my overall results, I partitioned the data according to several selected strata when such partitioning was possible. The strata were sex (male, female), mean years of age ( 65, 65), days of sampling ( 3, 3), and country (United States, Japan). The strata differentiation for days of sampling was based on the conclusion of Tudor-Locke et al that any 3 days can provide a sufficient estimate. 55(p293) The number of studies outside the United States and Japan was deemed insufficient to warrant stratification. If the 95% CIs for comparisons were not overlapping, the difference between strata was considered to be statistically significant. All analyses were conducted using SPSS for Windows (version 11.0)* and the meta-analytic syntax for SPSS developed by Wilson. 56 Results The electronic searches identified between 31 (PsycINFO) and 193 (Science Citation Index) potentially relevant articles. My examination of the articles revealed that 42 articles published between 1983 and 2004 were appropriate for inclusion A description of the studies is shown in Table 1. The number of subjects participating in individual studies ranged from 8 to 1,151. Most subjects were North American or Japanese, but some were from Europe or Australia. Studies did not always categorize (subdivide) subjects by sex, age, race or ethnicity, level of function or exercise, and nature of work. The type of pedometer used to monitor steps was not always identified or described thoroughly. Of the pedometers identified, the Yamax Digi- Walker SW-200 (or some name variation) was used most often. The time over which steps were sampled ranged from 1 day to 1 year, with 7 days being the mode (22 studies). Outcomes for the entire sample and those of selected strata are presented in Table 2. For the entire sample of 42 studies (6,199 subjects), the mean number of daily steps ranged from a low of 3,766 for Americans 65 or * SPSS Inc, 233 S Wacker Dr, Chicago, IL Yamax Corp, Tamachi KS Bldg, 5F , Shibaura, Minato-ku, Tokyo , Japan. more years of age 12 to a high of 18,425 for Amish men. 51 The results from these different studies were homogeneous. That is, their nonsignificant Q score suggests that the studies represent samples from a common population and that coalescing of their data was justified (Q 67.9, P.550). The overall number of steps per day for all of the studies averaged 9,501. The weighted standard deviation was 2,295 daily steps, and the 95% CI was 8,955 to 10,047 daily steps. The homogeneity of the studies notwithstanding, the mean number of steps taken by Amish men (18,425) and women (14,196) was more than 2 standard deviations beyond the mean for the remainder of the sample and thus were excluded from comparisons among strata. Data for each stratified variable (eg, age) also were homogeneous, indicating that subjects within the strata were from a common population. Nonetheless, there was a statistically significant difference between age strata. Specifically, the group with a mean age of less than 65 years took significantly more steps than the group with a mean age of 65 years. Discussion Although a criterion reference of 10,000 daily steps has been recommended 5 and numerous studies have been published that described the number of steps taken daily by adults, I believe that this is the first article to quantitatively summarize literature in an effort to estimate the number of steps that adults actually take. The mean steps for some groups described in the literature (most notably the Amish) 21,24,43 51 exceeded the 10,000-step criterion. For the Amish, who eschew some labor-saving technology such as automobiles, a larger step number should be expected. Using the classification scheme of Tudor-Locke and Bassett, 5 the average number of steps for all subjects from all studies 1644 f Physical Therapy Volume 87 Number 12 December 2007

4 Table 1. Pertinent Data From Included Studies Reference Subjects Measurement Steps Per Day (X SD) Yanagimoto et al (2000) 10 Petrella et al (2004) female Japanese (age [X SD] 78 8 y) 14 female and 6 male Americans (age y for 10 lowfunctioning subjects and y for 10 high-functioning subjects) Tudor-Locke et al (2004) female Americans (age y) and 76 male Americans (age y) Fukukawa et al (2004) 13 Wyatt et al (2004) 14 Brach et al (2003) 15 Whitt et al (2003) 16 Bassett et al (2000) female and male Japanese (age y) and 314 female and male Japanese (age y) 450 female and male Americans, work site; 202 female and male Americans, church 163 female Americans (age y) 137 female African Americans, 129 female Native Americans, 50 female Caucasian Americans (age y for all 316 women) 48 female Americans (age y), 48 male Americans (age y) Bassey et al (1988) female English (age y), 58 male English (age y) Tudor-Locke et al 23 female African Americans (2001) 19 (age y), 45 female Caucasian Americans (age y), 8 male African Americans (age y), 33 male Caucasian Americans (age y) Wilkinson et al (2004) 20 Bassey et al (1987) female Americans (age y) 10 female and male English medical school workers (age y) and 24 female English fitness class participants (age y) Calorie Counter Select II (2 wk) DigiWalker Stepcounter (7 d) Yamax SW-200 (7 d) Select II (7 d) Not stated (7 d) (7 d) Yamax (4 d) Yamax DW-500 (7 d) Not stated (7 d) DW-500 (21 d) SW-200 (3 d) Yamasa Digi-Walker (10 d, school workers; 6 d, fitness participants) 5,003 3,182 5,048 2,917 (low functioning) 9,502 4,623 (high functioning) 5,210 3,518 (female) 7,192 3,596 (male) 6,628 3,375 (white) a 4,792 3,874 (nonwhite) a 6,283 3,123 (age y) a 6,866 3,773 (age y) a 6,319 3,848 (age y) a 3,766 2,905 (age 65 y) a 5,281 2,214 (older) 6,395 2,438 (middle aged) 5,896 4,136 (church) 7,669 3,033 (work site) 5,425 3,153 5,435 2,849 5,569 2,093 (male) 6,413 2,267 (female) 6,000 4,000 (female) 7,143 3,857 (male) 6,198 2,735 (female, African American) 7,494 3,167 (female, Caucasian American) 7,654 3,079 (male, African American) 7,948 3,106 (male, Caucasian American) 6,262 2,712 6,417 2,800 fitness class participants 10,910 4,330 school workers (Continued) December 2007 Volume 87 Number 12 Physical Therapy f 1645

5 Table 1. Continued Reference Subjects Measurement Steps Per Day (X SD) Zhang et al (2003) female and 372 male Japanese without exercise habit (age y) Yamasa EC-500 (3 d) 6,603 2,938 (female, age y) 6,962 2,816 (female, age y) 8,053 3,695 (male, age y) 8,296 3,848 (male, age y) Chan et al (2004) 23 Fukuoka et al (2002) 24 Okuno et al (2004) 25 Speck et al (2001) 26 Wilde et al (2001) 27 Voorrips et al (1991) 28 Yamakawa et al (2004) female and 14 male Canadians (age y) 32 female and 31 male Japanese (age y) 73 female Japanese (age y) and 29 male Japanese (age y) 25 female Americans (age y) 32 female Americans (age y) 30 female and male Dutch (age y) 30 female and male Americans (age y) Yamax SW-200 (3 d) Omruron HJ-3 (7 d) Not stated (7 day) Yamax 701 (12 wk) Yamax SW-200 (2 d) Fitty, Kasper, and Richter (3 d) SW-701 (7 d) 6,981 3,140 (female) 7,661 2,474 (male) 7,072 3,913 (male, age y) 7,530 2,380 (male, age y) 8,526 2,915 (female, age y) 8,759 2,001 (male, age y) 9,312 1,907 (male, age y) 9,639 4,019 (female, age y) 10, (female, age y) 11,110 2,765 (male, age y) 11,415 5,452 (female, age y) 13,207 4,037 (female, age y) 7,059 3,156 (male) 7,257 2,623 (female) 7,103 2,018 7,220 2,406 7,335 4,369 7,385 3,680 Belcher et al (1997) female and 20 male Americans Sportline 345 (7 d) 7,607 2,859 (mean age 43 y, range 22 68) Visser et al (1995) female Dutch (age 74 3 y) Kasper and Richter (1 d) 7,757 3,350 Ichihara et al (1996) female Japanese (age y), 282 male Japanese (age y) Calorie Counter (7 d) 7,762 3,301 (female) 8,107 2,922 (male) McClung et al (2000) 33 Thompson et al (2004) female and 23 male Americans (age y) 80 female Americans (age y) Not stated (7 d) Digi-Walker SW-200 (7 d) 7,781 2,807 8,354 3,249 (Continued) 1646 f Physical Therapy Volume 87 Number 12 December 2007

6 Table 1. Continued Reference Subjects Measurement Steps Per Day (X SD) Kitagawa et al (2003) female Japanese (age y) Miller and Brown 111 female and 74 male (2004) 36 Australians (age y) Croteau (2004) female and 8 male Americans (age y) Sieminski and Gardner (1997) male and 13 female Americans (age y) Sequeira et al (1995) 39 Aittasalo et al (2004) 40 Schneider et al (2004) female and 265 male Swiss (age y) 87 female and 68 male Finnish (age y) 10 female Americans (age y) and 10 male Americans (age y) Tudor-Locke et al (2002) female and 27 male Americans (age y) Kashiwazaki et al (1986) male Japanese clerical workers (age y) and 13 male Japanese assembly-line workers (age y) Tudor-Locke et al 23 female and male Americans (2004) 44 (age y) Irimagawa and Imamiya 12 female Japanese nurses (1993) 45 (age y) Bassey et al (1983) 46 Welk et al (2000) 47 Patrick et al (1985) 48 Le Masurier et al (2004) 49 Inoue (1996) 50 Bassett et al (2004) female and male English factory workers (age y) 30 female and male Americans (age y) 12 male English (age y) 6 female Americans (age y) and 6 male Americans (age y) 8 male Japanese (age y) 45 female Canadian Amish (age y) and 53 male Canadian Amish (age y) a All outcomes except these were used in the meta-analysis. Omruron HJ-002 (7 d) Yamax SW 700 (7 d) (7 d) Omron (2 d) Pedoboy (7 d) (7 d) SW-200 (13 d) SW-200 (7 d) Yamasa DX-1 (1 d) Yamax SW 200 (1 y) Dowalk-EP43 (1 d) Not stated (7 d) Digi-Walker (7 d) Yamasa Digiped (6 d) Yamax SW-200 (1 d) Not stated (2 wk) SW-200 (7 d) 8,401 3,404 8,543 2,466 (male) 9,093 2,926 (female) 8,565 3,121 (male and female) 8,672 4,235 (male and female) 8,900 3,200 (female) 10,400 4,700 (male) 9,064 3,141 (male and female) 9,244 3,727 (male and female) 9,638 4,030 (male and female) 10,571 4,336 clerical workers 11,294 2,336 assembly workers 10,090 3,389 11,478 1,285 11, ,603 5,087 11,800 6,235 12,359 4,201 13,800 6,505 14,196 4,078 (female) 18,425 4,685 (male) December 2007 Volume 87 Number 12 Physical Therapy f 1647

7 Table 2. Overall and Subgroup Results for Daily Steps Data Sets (n) a Subjects No. of Steps Homogeneity (n) b Weighted Weighted 95% CI c Q P Mean SD All (71) 6,199 9,501 2,295 8,955 10, All except Amish (67) 6,101 9,448 2,218 8,899 9, Age Mean age 65 y (54) 4,899 9,797 2,026 9,216 10, Mean age 65 y (15) 1,202 6,565 1,530 4,897 8, Sex Men (20) 1,325 8,412 1,579 7,165 9, Women (29) 2,338 8,735 2,210 7,821 9, Sex and age Men: mean age 65 y (18) 1,238 8,509 1,594 7,217 9, Men: mean age 65 y (2) 87 7, ,305 11, Women: mean age 65 y (21) 1,789 9,091 2,117 8,095 10, Women: mean age 65 y (8) 549 6,855 1,674 4,567 9, Country Japan (26) 2,783 9,317 2,034 8,403 10, United States (28) 2,107 7,271 1,553 6,123 8, Days sampled 3 (7) ,657 1,607 8,811 12, (62) 5,963 9,331 2,234 8,757 9, a Some studies contributed multiple data sets. b Not all studies delineated all strata, so the total n (excluding Amish) does not always 6,101. c CI confidence interval. together in this meta-analysis would place them within the somewhat active category (7,500 9,999 steps per day). One of the most notable findings of this study was the lower mean number of steps taken per day (6,565) by adults with a mean age of 65 years or older. The mean number of steps of these older adults would place them in the low active category (5,000 7,499 steps per day) of Tudor-Locke and Bassett. 5 Although the lower number recorded for older adults could be influenced by their slower gait, which is less likely to trigger the pedometer to record a step, 57 I doubt that this explains all or most of the lower step number in the ostensibly healthy older adult population incorporated into this meta-analysis. Patient- or client-related instruction, one of the roles of physical therapists, 58 might include information on the health benefits of walking for older adults. Among such benefits are lowered blood pressure, weight loss, reduced waist circumference, and improved glucose tolerance, 7,8,59 61 Once a pedometer has been used to quantify daily their steps, they will have access to accurate information that will allow them to compare the number of steps they take relative to both the normative values presented in this article and the 10,000-step criterion. Meta-analysis, like any type of research or review, has limitations. One limitation was the samples of data contributing to this metaanalysis. To the best of my knowledge, no study contributing to the analysis utilized a random sample from the population. Such a sample would provide a more representative indication of normal than the convenience samples used in the included studies. In any case, this meta-analysis should provide a better estimate of daily steps than is provided by any single study. A second limitation of this study was the different pedometers used to measure steps as well as the lack of specificity provided by some studies 1648 f Physical Therapy Volume 87 Number 12 December 2007

8 about the pedometer used. Previous research 41 has shown that the validity and reliability of data obtained with pedometers vary. The largest number of studies used either the SW-200 or the SW-701, both of which have been shown to accurately reflect the number of steps taken. 41,62 However, some studies did not specifically indicate the pedometer used, or they used other pedometers to measure steps. The former factor made sensitivity analysis in regard to pedometer use impracticable. A third limitation may have been the number of days over which steps were monitored. Tudor-Locke et al 55 suggested that a single day of step monitoring is not acceptable but that 3 days provide a sufficient estimate. Several of the studies included in this meta-analysis monitored steps for only 1 or 2 days. The sensitivity analysis, however, did not find any difference when results were partitioned according to whether the data were collected for less than 3 days or for 3 or more days. A fourth limitation of the study was its inability to provide complete summary data for specific strata. Often the necessary breakdown of information (eg, men versus women) from the contributing studies was not provided. When information was provided, it was not always specific. Consequently, I had to use discrete categories (ie, mean age of 65 years versus 65 years) rather than more specific categories (eg, decades) that often are used to establish normative reference values. More representative and refined normative reference values than could be derived from my meta-analysis are warranted. Such values would need to be obtained from a large population-based sample that could be divided into strata based on variables such as age, sex, ethnicity, and living environment. In conclusion, the number of steps taken per day by adults is typically less than the 10,000 that have been recommended. This is particularly the case for elderly people. This information can be used by physical therapists and others engaged in health promotion. This article was submitted February 1, 2006, and was accepted July 20, DOI: /ptj References 1 Physical Activity and Health: A Report of the Surgeon General. Atlanta, Ga: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion; Eyler AA, Brownson RC, Becak SJ, Housemann RA. The epidemiology of walking for physical activity in the United States. Med Sci Sports Exerc. 2003;35: McPhillips JB, Pellettera KM, Barrett- Connor E, et al. Exercise patterns in a population of older adults. Am J Prev Med. 1989;2: Hamdorf P, Starr G, Williams M. A survey of physical-activity levels and functional capacity in older adults in South Australia. J Aging Phys Act. 2002;10: Tudor-Locke CE, Bassett DR. How many steps per day are enough? Preliminary pedometer indices for public health. Sports Med. 2004;34: LeMasurier GC, Sidman CL. Corbin CB. Accumulating 10,000 steps: does this meet current physical activity guidelines? Res Q Exerc Sport. 2003;74: Iwane M, Arita M, Tomimoto S, et al. Walking 10,000 steps/day or more reduces blood pressure and sympathetic nerve activity in mild essential hypertension. Hypertens Res. 2000;23: Schneider PL, Bassett DR, Thompson DL, et al. Effects of 10,000 steps per day goal in overweight adults. Am J Health Promot. 2006;21: Rothstein JM, Echternach JL. Primer on Measurement: An Introductory Guide to Measurement Issues. Alexandria, Va: American Physical Therapy Association; Yanagimoto Y, Oshida Y, Sato Y. Effects of walking on bone quality as determined by ultrasound in the elderly. Scand J Med Sci Sports. 2000;10: Petrella JK, Cress ME. Daily ambulation activity and task performance in community dwelling older adults aged years with preclinical disability. J Gerontol A Biol Sci Med Sci. 2004;59: Tudor-Locke CE, Ham SA, Macera CA, et al. Descriptive epidemiology of pedometer-determined physical activity. Med Sci Sports Exerc. 2004;36: Fukukawa Y, Nakashima C, Tsuboi S, et al. Age differences in the effect of physical activity on depressive symptoms. Psychol Aging. 2004;19: Wyatt HR, Peters JC, Reed GW, et al. Using electronic step counters to increase lifestyle physical activity: Colorado on the Move TM. J Phys Activity Health. 2004; 1: Brach JS, Fitzgerald S, Newman AB, et al. Physical activity and functional status in community-dwelling older women. Arch Intern Med. 2003;163: Whitt MC, Levin S, Ainsworth BE, Dubose KD. Evaluation of a two-part survey item to assess moderate physical activity: the Cross-Cultural Activity Participation Study. J Womens Health. 2003;12: Bassett DR, Cureton AL, Ainsworth BE. Measurement of daily walking distancequestionnaire versus pedometer. Med Sci Sports Exerc. 2000;32: Bassey EJ, Bendall MJ, Pearson M. Muscle strength in the triceps surae and objectively measured customary walking activity in men and women over 65 years of age. Clin Sci. 1988;74: Tudor-Locke CE, Ainsworth BE, Whitt MC, et al. The relationship between pedometerdetermined ambulatory activity and body composition variables. Int J Obesity. 2001; 25: Wilkinson S, Huang C-M, Walker LO, et al. Physical activity in low-income postpartum women. J Nurs Scholarsh. 2004;36: Bassey EJ, Dallosso HM, Fentem PH, et al. Validation of a simple walking mechanical accelerometer (pedometer) for the estimation of walking activity. Eur J Appl Physiol. 1987;56: Zhang J-G, Ohta T, Ishikawa Takata K, et al. Effects of daily activity recorded by pedometer on peak oxygen consumption (V O2 peak), ventilatory threshold and leg extension power in 30- to 69- year-old Japanese without exercise habit. Eur J Appl Physiol. 2003;90: Chan CB, Ryan DAJ, Tudor-Locke C. Health benefits of a pedometer-based physical activity intervention in sedentary workers. Prev Med. 2004;39: Fukuoka Y, Nakagawa Y, Ogoh K, et al. Dynamics of the heart rate response to sinusoidal work in humans: influence of physical activity and age. Clin Sci. 2002;102: Okuno J, Nishiki M, Matsuda M, et al. Relationship between subjective usefulness of pedometer and step counts, exercise adherence in the community-dwelling elderly. Jpn J Phys Fitness Sports Med. 2004;53: December 2007 Volume 87 Number 12 Physical Therapy f 1649

9 26 Speck BJ, Looney SW. Effects of a minimal intervention to increase physical activity in women. Nurs Res. 2001;50: Wilde BE, Sidman CL, Corbin CB. A 10,000-step count as a physical activity target for sedentary women. Res Q Exerc Sport. 2001;72: Voorrips LE, Ravelli ACJ, Dongelmans PCA, et al. A physical activity questionnaire for the elderly. Med Sci Sport Exerc. 1991;23: Yamakawa K, Tsai CK, Haig AJ, et al. Relationship between ambulation and obesity in older persons with and without low back pain. Int J Obes. 2004;28: Belcher GL, Radomisli TE, Abate JA, et al. Functional outcome analysis of operatively treated malleolar fractures. J Orthop Trauma. 1997;11: Visser M, DeGroot LC, Deurenberg P, Van Stavaren WA. Validation of dietary history method in a group of elderly women using measurements of total energy expenditure. Br J Nutr. 1995;74: Ichihara Y, Hattori R, Anno T, et al. Oxygen uptake and its relation to physical activity and other coronary risk factors in asymptomatic middle-aged Japanese. J Cardiopulm Rehabil. 1996;16: McClung CD, Zahiri CA, Higa JK, et al. Relationship between body mass index and activity in hip or knee arthroplasty patients. J Orthop Res. 2000;18: Thompson DL, Rakow J, Perdue SM. Relationship between accumulated walking and body composition in middle-aged women. Med Sci Sports Exerc. 2004; 36: Kitagawa J, Omasu F, Nakahara Y. Effect of daily walking steps on ultrasound parameters of the calcaneus in elderly Japanese women. Osteoporos Int. 2003;14: Miller R, Brown W. Meeting physical activity guidelines and average daily steps in a working population. J Phys Act Health. 2004;1: Croteau KA. A preliminary study on the impact of a pedometer-based intervention on daily steps. Am J Health Promot. 2004;18: Sieminski DJ, Gardner AW. The relationship between free-living daily physical activity and the severity of peripheral arterial occlusive disease. Vasc Med. 1997;2: Sequeira MM, Rickenbach M, Wietlisbach V, et al. Physical activity assessment using a pedometer and its comparison with a questionnaire in a large population survey. Am J Epidemiol. 1995;142: Aittasalo M, Miilunpalo S, Suni J. The effectiveness of physical activity counseling in a work-site setting: a randomized, controlled trial. Patient Educ Counsel. 2004; 55: Schneider PL, Crouter SE, Bassett DR. Pedometer measures of free-living physical activity: comparison of 13 models. Med Sci Sports Exerc. 2004;36: Tudor-Locke CE, Ainsworth BE, Thompson RW, Matthews CE. Comparison of pedometer and accelerometer measures of free-living physical activity. Med Sci Sports Exerc. 2002;34: Kashiwazaki H, Inaoka T, Suzuki T, Kondo Y. Correlations of pedometer readings with energy expenditure in workers during free-living daily activities. Eur J Appl Physiol. 1986;54: Tudor-Locke CE, Bassett DR, Swartz AM, et al. A preliminary study of one year of pedometer self-monitoring. Ann Behav Med. 2004;28: Irimagawa S, Imamiya S-I. Industrial hygienic study on nursing activities comparison of energy expenditure between pedometer and holter electrocardiograph. Kitasato Arch Exp Med. 1993;65 (suppl): Bassey EJ, Patrick JM, Irving JM, et al. An unsupervised aerobics physical training program in middle-aged factory workers: feasibility, validation, and response. Eur J Appl Physiol. 1983;52: Welk GJ, Differding JA, Thompson RW, et al. The utility of the Digi-Walker step counter to assess daily physical activity patterns. Med Sci Sports Exerc. 2000; 32:S481 S Patrick JM, Wharrad HJ, Wilson CG, Birmingham AT. The effect of a week s -adrenoceptor antagonism on daytime heart-rates, subjective responses to exercise, and physical activity in normal subjects. Br J Clin Pharmacol. 1985;19: Le Masurier GC, Lee SM, Tudor-Locke C. Motion sensor accuracy under controlled and free-living conditions. Med Sci Sports Exerc. 2004;36: Inoue Y. Longitudinal effects of age on heat-activated sweat gland density and output in healthy active older men. Eur J Appl Physiol. 1996;74: Bassett DR, Schneider PL, Huntington GE. Physical activity in an older Amish community. Med Sci Sports Exerc. 2004; 36: Tudor-Locke CE, Myers AM. Methodological considerations for researchers and practitioners using pedometers to measure physical (ambulatory) activity. Res Q Exerc Sport. 2001;72: Hedges LV, Olkin I. Statistical Methods for Meta-Analysis. San Diego, Calif: Academic Press; Sacks HS, Berrier J, Reitman D, et al. Metaanalysis of randomized controlled trials. N Engl J Med. 1987;316: Tudor-Locke CE, Burkett L, Reiss JP, et al. How many days of pedometer monitoring predict weekly physical activity in adults? Prev Med. 2005;40: Wilson DB. Meta-Analysis Stuff. Available at: dwilsonb/home. html. Accessed June 20, Cyarto EV, Myers AM, Tudor-Locke CE. Pedometer accuracy in nursing home and community-dwelling older adults. Med Sci Sports Exerc. 2004;36: Guide to Physical Therapist Practice. Phys Ther. 1997;77: Tudor-Locke CE, Myers AM, Bell RC, et al. Preliminary outcome evaluation of the First Step Program: a daily physical activity intervention for individuals with type 2 diabetes. Patient Educ Couns. 2002;47: Moreau KL, Degarmo R, Langley J, et al. Increasing daily walking lowers blood pressure in postmenopausal women. Med Sci Sports Exerc. 2001;33: Swartz AM, Strath SJ, Bassett DR, et al. Increasing daily walking improves glucose tolerance in overweight women. Prev Med. 2003;37: Schneider PL, Crouter SE, Lukajic O, Bassett DR. Accuracy and reliability of 10 pedometers for measuring steps over 400-m walk. Med Sci Sports Exerc. 2003;35: f Physical Therapy Volume 87 Number 12 December 2007