Sandra A. Ham

Descriptive epidemiology of pedometer-determined physical activity

PURPOSE The dual purposes of this study were: 1) to provide preliminary descriptive epidemiology data representing pedometer-determined physical activity (PA) and 2) to explore sources of intra-individual variability in steps per day. METHODS All participants (76 males, age = 48.4 +/- 16.3 yr, body mass index (BMI) = 27.1 +/- 5.1 kg x m(-2); 133 females, age = 47.4 +/- 17.5 yr, BMI = 26.9 +/- 5.7 kg x m(-2)) resided in Sumter County, SC, and were recruited by telephone to receive a mailed kit to self-monitor PA for 1 wk. Statistical analyses compared mean steps per day between sexes, races, age groups, education and income levels, and BMI categories. Mean steps per day were also compared between: 1) weekdays versus weekend days, 2) workdays versus nonworkdays, and 3) days of sport/exercise versus no participation. RESULTS The entire sample took 5931 +/- 3664 steps x d(-1) (males = 7192 +/- 3596 vs females = 5210 +/- 3518 steps x d(-1), t = 7.88, P < 0.0001). Significant differences were also indicated by race, age, education, income, and BMI. In addition, weekdays were significantly higher than weekend days, workdays were higher than nonworkdays, and sport/exercise days were higher than nonsport/exercise days. CONCLUSIONS The large standard deviations reflect a wide distribution of ambulatory behavior. Regardless, important differences are still evident by demographic characteristics, BMI categories, day of the week, and reported engagement in work or sport/exercise.

Increasing Stair Use in a Worksite Through Environmental Changes

Purpose. This study assessed the impact on stair use of four sequential environmental interventions: (1) installing new carpet and painting the walls, (2) adding framed artwork on stair landings, (3) displaying motivational signs throughout the building, and (4) adding a stereo system and playing various types of music in the stairwell. Methods. We conducted a longitudinal study with no comparison group to evaluate the impact of environmental changes on stairway use. The setting was the main stairwell in the Centers for Disease Control and Preventions (CDC) Rhodes Building in Atlanta, Georgia. Proximity sensors were installed in each stairwell entry to monitor traffic. The subjects were 554 permanent CDC employees and 110 temporary employees. Changes in stairwell use by intervention were evaluated. Results. Both motivational signs and music significantly increased stair use by 8.9% over baseline (p < .05). The increase in sign use occurred in the first 3 months of the intervention, whereas the increase in music occurred after the first 3 months. Discussion. These data suggest that physical improvements to a stairwell, signage that encourages stair use, and music may increase physical activity among building occupants.

Prevalence of transportation and leisure walking among u.s. adults

OBJECTIVE This paper aims to contrast the demographic correlates of leisure and transportation walking. METHODS Using data from the 2005 National Health Interview Survey (n=31,482), this paper reports on the prevalence of transportation walking and leisure walking for U.S. adults and examines the variation in prevalence across different socio-demographic groups. The prevalence of transportation walking and leisure walking for U.S. adults (> or =5 days/week for > or =30 min/day) was calculated using data from the 2005 National Health Interview Survey. RESULTS In the United States, 41.5% of adults walked for leisure and 28.2% walked for transportation in intervals of at least 10 min. The highest prevalence of transportation walking was among black non-Hispanic men (36.0%) and Asian/Native Hawaiian/Pacific Islander women (40.5%). The highest prevalence of leisure walking was among Asian/Native Hawaiian/Pacific Islander men (42.0%) and white non-Hispanic women (46.6%). Leisure walking was most prevalent among respondents with higher incomes and education levels, whereas transportation walking increased in prevalence with education level but decreased with income level. Based on the findings, 6% of U.S. adults were considered regularly active (> or =5 days/week for > or =30 min/day) by walking for transportation and 9% were regularly active by walking for leisure. CONCLUSION Leisure and transportation walking have distinctly different demographic correlates. These differences should guide interventions aimed at influencing walking for different purposes.

A sex difference in the predisposition for physical competition: males play sports much more than females even in the contemporary U.S.

Much evidence indicates that men experienced an evolutionary history of physical competition, both one-on-one and in coalitions. We thus hypothesized that, compared to girls and women, boys and men will possess a greater motivational predisposition to be interested in sports, especially team sports. According to most scholars, advocacy groups, and the United States courts, however, this hypothesis is challenged by modest sex differences in organized school sports participation in the contemporary U.S., where females comprise 42% of high school participants and 43% of intercollegiate participants. We conducted three studies to test whether organized school sports participation data underestimate the actual sex difference in sports participation. Study 1 analyzed the American Time Use Survey, which interviewed 112,000 individuals regarding their activities during one day. Females accounted for 51% of exercise (i.e., non-competitive) participations, 24% of total sports participations, and 20% of team sports participations. These sex differences were similar for older and younger age groups. Study 2 was based on systematic observations of sports and exercise at 41 public parks in four states. Females accounted for 37% of exercise participations, 19% of individual sports participations, and 10% of team sports participations. Study 3 involved surveying colleges and universities about intramural sports, which primarily consist of undergraduate participation in team sports. Across 34 institutions, females accounted for 26% of registrations. Nine institutions provided historical data, and these did not indicate that the sex difference is diminishing. Therefore, although efforts to ensure more equitable access to sports in the U.S. (i.e., Title IX) have produced many benefits, patterns of sports participation do not challenge the hypothesis of a large sex difference in interest and participation in physical competition.

Assessment of physical activity by telephone interview versus objective monitoring

PURPOSE To compare different methods of quantifying time in physical activity (PA). METHODS Twenty-five participants (12 male, 13 female) volunteered to be monitored for seven consecutive days, during which different PA patterns were measured by the simultaneous heart-rate motion sensor technique (HR+M). At the end of the 7th day, participants completed questions taken from the 2001 Behavioral Risk Factor Surveillance System (BRFSS) PA module telephone survey, in which they recalled the amount of time spent walking, and in moderate and vigorous activities. The results of the BRFSS PA module were then compared with those of the HR+M. RESULTS No significant group differences were found in the amount of time spent in moderate and vigorous activities between methods. However, individual differences were greater for time spent in moderate activities (SE +/- 7.36 min x d(-1); range -70 to 77 min x d(-1)) than for time spent in vigorous activities (SE +/- 3.57 min x d(-1); range -39 to 33 min x d(-1). Spearman correlation coefficients between the HR+M and the BRFSS were significant for vigorous activities (r = 0.54, P < 0.01). There was 80% agreement between the two methods of classifying individuals who either: (a) met the recommendations (through moderate and/or vigorous PA) or (b) did not meet the recommendations. CONCLUSION The BRFSS and HR+M methods yielded similar group estimates of PA, but individual assessments of moderate activity differed more than those of vigorous activity. BRFSS estimations of group compliance with national PA recommendations were similar to those of the HR+M.

Limitations on the Use of a Single Screening Question To Measure Sedentary Behavior.

OBJECTIVES This study explored the limitations of identifying sedentary individuals via an existing screening question in a state-based surveillance system. METHODS A national sample (n = 7529) of adults, selected by random-digit dialing between November 1999 and May 2000, responded about participation in leisure-time physical activity. RESULTS Of those who initially reported no leisure-time physical activity (25%), 85% were engaging in at least some activity, and 20% were engaging in enough moderate- or vigorous-intensity activity to meet health-related recommendations. CONCLUSIONS Public health programs that use only 1 screening question to identify sedentary behavior may not be able to target physical activity messages effectively, especially if physical activity is defined to include a broad range of activities beyond sports.

Instant Recess®: A Practical Tool for Increasing Physical Activity During the School Day

Background: An increased prevalence of overweight/obesity among children has led to school district level policies to increase physical activity (PA) among elementary school students. Interventions are needed that increase activity levels without sacrificing time spent in academics. Objectives: We evaluated a policy implementation intervention for to increase in-school PA in elementary schools in Forsyth County, North Carolina, in a randomized study with a delayed intervention control group. Methods: The study included third- through fifth-grade classrooms in eight elementary schools. Instant Recess® was used to introduce 10-minute PA breaks in classrooms on schedules determined by teachers. Direct observation was used to measure activity levels, other student behaviors, and teacher behaviors related to PA in the classrooms. Results: Twenty-eight visits to schools were made during the spring and fall semesters of 2009. At baseline 11% to 44% of intervention and control schools were engaged in classroom-based PA. PA increased from baseline to spring follow-up in intervention schools and was maintained the following fall. Control schools decreased PA from baseline to spring and increased PA once they began the intervention. Students in classrooms engaged in Instant Recess exhibited statistically significant increases in light (51%) and moderate-intensity (16%) PA and increases in time spent in on-task behavior (11%). Control schools experienced similar benefits after they began implementing Instant Recess. Conclusions:Instant Recess is useful for increasing PA and improving behavior among elementary school children. Additional research may be needed to understand how to create policies supporting classroom activity breaks and how to assess policy adherence.

The Reliability of a Survey Question on Television Viewing and Associations With Health Risk Factors in US Adults

Research into the accuracy of self‐reported measures used to quantify physical inactivity has been limited. The purposes of the current report were to examine the reliability of a survey question assessing time spent watching television and to describe associations between television watching and physical activity and health risk factors. Data from this cross‐sectional investigation were obtained from a study designed to evaluate a physical activity module for potential use in the 2001 Behavioral Risk Factor Surveillance System. Participants were 93 men and women (aged 45.9 (15.4) years) who answered the question pertaining to television watching during an initial visit and three follow‐up visits to the study center. Intra‐class correlation coefficients (ICCs) between administrations of the survey question were used to assess test‐retest reliability. Spearman rank order correlation coefficients were used to examine the associations of television viewing with physical activity and health risk factors. The test‐retest reliability of the television‐watching question suggested moderate agreement (ICCs of 0.42 and 0.55 over a 3‐week and 1‐week period, respectively). After adjustment for age and sex, reported television‐watching hours were positively associated with BMI (P = 0.0002), percentage fat (P = 0.0001), and light‐intensity physical activity (P = 0.006) and negatively associated with cardiorespiratory fitness (P = 0.004) and moderate‐intensity and hard‐intensity physical activity (P = 0.03 and P = 0.003, respectively). Increased time spent in sedentary behaviors has been identified as a major modifiable risk factor in the development of chronic diseases and conditions. The single‐item survey question evaluated in this study was shown to be a reliable measure of television watching and was associated with physical activity and health risk factor outcomes.

Ranking of Cities According to Public Health Criteria: Pitfalls and Opportunities

Popular magazines often rank cities in terms of various aspects of quality of life. Such ranking studies can motivate people to visit or relocate to a particular city or increase the frequency with which they engage in healthy behaviors. With careful consideration of study design and data limitations, these efforts also can assist policymakers in identifying local public health issues. We discuss considerations in interpreting ranking studies that use environmental measures of a city populations public health related to physical activity, nutrition, and obesity. Ranking studies such as those commonly publicized are constrained by statistical methodology issues and a lack of a scientific basis in regard to design.

Trends in Walking for Transportation in the United States ??? 1995 and 2001

Introduction The purpose of this study was to examine trends in walking for transportation among U.S. adults and youth for Healthy People 2010 objective 22-14. The objective calls for increasing the proportion of trips of 1 mile or less made by walking to 25% for adults and 50% for youth. National transportation surveys are used to track national health objectives, but data interpretation and caveats to use have not been discussed in the public health literature to date. Methods Cross-sectional analyses at two time points used data from the 1995 Nationwide Personal Transportation Survey and the subsequent 2001 National Household Travel Survey. The populations of interest were U.S. civilian noninstitutionalized adults (aged 18 years and older) and youth (aged 5 to 15 years). Trends were reported for the percentage of walking trips of 1 mile or less for transportation (adults) and walking trips of 1 mile or less to school (youth) using 86,286 trips (1995) and 119,462 trips (2001) made by adults and 3114 trips (1995) and 4073 trips (2001) made by youth. Results Of trips of 1 mile or less, adults reported more walking in 2001 (21.2%; 95% confidence interval [CI], 20.5–21.9) than in 1995 (16.7%; CI, 15.9–17.5). For trips to school of 1 mile or less, youths also increased walking from 1995 (31.3%; CI, 27.9–34.4) to 2001 (35.9%; CI, 33.0–38.8). Changes in survey methodology affected the interpretation of the Healthy People 2010 trends. Conclusion In spite of small increases in walking between 1995 and 2001 accompanying a change in survey methodology, U.S. adults and youth fall short of meeting Healthy People 2010 walking objectives for trips of 1 mile or less.