A Method for Observing Physical Activity on Residential Sidewalks and Streets

Assessment of physical activity needs to improve in order to gain a more comprehensive understanding of the relationship between characteristics of the environment and physical activity. Our study evaluated a method [Block Walk Method (BWM)] for observing physical activity along residential sidewalks and streets. The BWM was utilized in 12 U.S. Census block groups over a three-month period. Examination transportation routes (ETRs), 1,524 m in length, were constructed and examined in each block group. On 6 days, ETRs were traversed by a trained observer for 50 min. Physical activities, street names, and geographical locations (e.g., addresses) were recorded. We found encouraging results for the BWM. The level of agreement between independent observers was >98% for activity type. The number of individuals seen walking, running, or biking did not differ significantly between the days of the week or observation times. The number of individuals observed was correlated with block group characteristics (e.g., percent walking/biking to work) and weather (e.g., temperature). The BWM is an easy to use, economically viable observational approach to obtaining reliable information concerning physical activities performed on residential streets and sidewalks. Its use could help advance our understanding about the environment–physical activity relationship.Suminski is with the School of Physical Activity and Educational Services, The Ohio State University, 155 Cunz Hall, Columbus, OH 43210, USA; Petosa and Stevens are with the School of Physical Activity and Educational Services, The Ohio State University, Columbus, OH 43026, USA.     

Characteristics of Urban Sidewalks/Streets and Objectively Measured Physical Activity

Several studies have found significant relationships between environmental characteristics (e.g., number of destinations, aesthetics) and physical activity. While a few of these studies verified that the physical activities assessed were performed in the environments examined, none have done this in an urban, neighborhood setting. This information will help efforts to inform policy decisions regarding the design of more “physically active” communities. Fourteen environmental characteristics of 60, 305-m-long segments, located in an urban, residential setting, were directly measured using standardized procedures. The number of individuals walking, jogging, and biking in the segments was assessed using an observation technique. The segments were heterogeneous with regards to several of the environmental characteristics. A total of 473 individuals were seen walking, bicycling, or jogging in the segments during 3,600 min of observation (60 min/segment). Of the 473 seen, 315 were walking, 116 bicycling, and 42 jogging. A greater number of individuals were seen walking in segments with more traffic, sidewalk defects, graffiti, and litter and less desirable property aesthetics. Only one environmental characteristic was associated with bicycling and none were significantly related with jogging. This study provides further evidence that environmental characteristics and walking are related. It also adds new information regarding the importance of scale (e.g., micro, macro) and how some environmental characteristics of urban, residential sidewalks and streets relate to physical activity. Suminski and Hyder are with the Department of Physiology, Kansas City University of Medicine and Biosciences, Kansas, MO, USA; Heinrich is with the Department of Public Health Sciences, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI, USA; Poston is with the Department of Basic Medical Sciences, University of Missouri-Kansas City School of Medicine, Kansas, MO, USA; Pyle is with the Department of Family Medicine, Kansas City University of Medicine and Biosciences, Kansas, MO, USA.     

Association of environmental factors to meeting physical activity recommendations in two South Carolina counties

PURPOSE: The purpose of the study was to examine associations between environment and policy factors and physical activity. DESIGN: A random-digit-dialed, cross-sectional telephone survey was administered. SETTING: The setting was a two-county area of eastern South Carolina. SUBJECTS: Before weighting, the sample included 1936 adults; 36.9% African-American, 63.1% white, and 60.1% women. The age group distribution was 28.8% 55+ years, 39.3% 35-54 years, and 31.9% 18-34 years of age. The response rate was 62.9%. MEASURES: Six physical activity questions (2001 Behavioral Risk Factor Surveillance Survey [BRFSS]) were used to create a dischotomous variable, "meets/does not meet recommendation for moderate or vigorous physical activity." Self-report items assessed knowledge, presence, and use of recreational facilities; presence of environmental and worksite supports; perceived safety; condition of sidewalks; and quality of street lighting. RESULTS: Linear and logistic regression were used to analyze the data. Unadjusted odds for meeting the recommendation were significantly greater for well-maintained sidewalks (OR = 1.90); safe areas for walking/jogging (OR = 1.39); knowledge of routes for bicycling (OR = 1.38) and walking/jogging (OR = 1.32); and worksites with sports teams (OR = 1.53), exercise facilities (OR = 1.33), flexible time for exercise (OR = 1.33), and preventive checkups (OR = 1.26). Among persons who met the recommendation, means were greater for number of known walking/jogging routes (p = .04); number of known bicycling routes (p < .01); number of days per month uses tracks, trails, routes, pathways (p < .01); and number of days per month uses outdoor recreation areas (p < .01). CONCLUSION: The results support an association between level of physical activity and environmental and policy factors in two southeastern counties in South Carolina. Limitations of the study include self-reported data and cross-sectional design.     

中国南方中青年体力活动能量消耗研究

目的研究中国南方中青年常见体力活动的能量消耗。方法通过问卷调查和体格检查筛选出轻体力活动健康中青年64名,采用k4b2便携式心肺功能测定仪测量其基础代谢和七项体力活动(慢走、快走、慢跑、骑自行车、上下楼梯和看电视)的耗氧量(VO2)和二氧化碳生成量(VCO2),用微量凯式定氮法测量24小时尿氮,利用Weir公式计算其能量消耗量。结果各项体力活动平均能量消耗量(kJ·h-1·kg-1)分别为:慢走14.77±2.47,快走22.18±3.68,慢跑41.34±7.32,骑自行车18.41±3.89,上楼梯26.11±4.18,下楼梯13.68±2.89,看电视5.06±1.09;男性各项体力活动能量消耗量均高于女性(P<0.05)。结论体力活动能量消耗差异较大,看电视为低强度体力活动,骑自行车、上下楼、慢走及快走为中强度体力活动,慢跑为高强度体力活动。     

Neighborhood design and walking. A quasi-experimental longitudinal study

BACKGROUND: Few studies have employed longitudinal data to examine associations between the physical environment and walking. METHODS: Using cross-sectional (n=70) and longitudinal (n=32) data (collected 2003-2006), associations of neighborhood design and demographics with walking were examined. Participants were low-income, primarily African-American women in the southeastern U.S. Through a natural experiment, some women relocated to neo-traditional communities (experimental group) and others moved to conventional suburban neighborhoods (control group). RESULTS: Post-move cross-sectional comparisons indicated that women in neo-traditional neighborhoods did not, on average, walk more than women in suburban neighborhoods. Race and household size were significant predictors of physical activity. Additionally, using longitudinal data, this study controlled for the effects of pre-move walking and demographics. Analyses examined the effects of environmental factors (e.g., density, land-use mix, street-network patterns) on post-move walking. Women who moved to places with fewer culs-de-sac, on average, walked more. Unexpectedly, increases in land-use mix were associated with less walking. CONCLUSIONS: Results suggest that neo-traditional neighborhood features alone (e.g., sidewalks, front porches, small set-back distances) may not be enough to affect walking; however, changes in street patterns may play a role.     

Obesity, physical activity, and the urban environment: public health research needs

Persistent trends in overweight and obesity have resulted in a rapid research effort focused on built environment, physical activity, and overweight. Much of the focus of this research has been on the design and form of suburbs. It suggests that several features of the suburban built environment such as low densities, poor street connectivity and the lack of sidewalks are associated with decreased physical activity and an increased risk of being overweight. But compared to suburban residents, inner city populations have higher rates of obesity and inactivity despite living in neighborhoods that are dense, have excellent street connectivity and who's streets are almost universally lined with sidewalks.     

Reliability and validity of two instruments designed to assess the walking and bicycling suitability of sidewalks and roads

PURPOSE: Public health professionals hypothesize that when community environments provide suitable walking and bicycling conditions, community members will be more active. Measurement indicators and assessment instruments are needed to evaluate suitability. This study determined the reliability and validity of two instruments to assess the suitability of sidewalks for walking and roads for bicycling. METHODS: Two data collectors used walking and bicycling suitability assessment instruments to collect data on 31 road segments. In addition, three transportation experts used a 7-point Likert response system to subjectively evaluate walking and bicycling conditions for the same segments. Intraclass correlations determined the reliability of each assessment instrument and the reliability of the Likert response system. Pearson correlations (research staff assessments with expert assessments) were calculated to determine the criterion-related validity of the suitability measures. RESULTS: Intercoder reliability (intraclass) correlations for the walking and bicycling assessment instruments were r = .79 and .90, respectively. Intercoder reliability of the experts' Likert response system was r = .73 for the walking form and r = .77 for the bicycling form. Criterion-related validity (Pearson) correlations for the walking and bicycling assessment instruments were r = .58 and .62, respectively. CONCLUSION: Although some variables have lower reliability and validity than is ideal, the walking and bicycling suitability assessment instruments appear promising as instruments for community members and professionals to systematically assess key aspects of the physical environment.     

A study of urban housing demolition as a source of lead in ambient dust on sidewalks, streets, and alleys

We examined changes in ambient dust lead (Pb) levels associated with the demolition of older row houses containing lead paint in Baltimore, MD, USA. Our previous paper describes the three study sites, the demolition processes, and increases in the Pb dustfall rate during demolition (>40-fold) and debris removal (>6-fold) within 10 m of sites where wetting was of limited effectiveness. This paper presents the analysis of settled dust collected using a cyclone device from streets, sidewalks, and alleys within 100 m of study sites before, immediately after, and 1 month after demolition. We found acute increases in Pb loadings and dust loadings after demolition and debris removal that are of public health concern. Streets and alleys had the greatest increases in Pb loadings and the highest levels overall. At one site, geometric mean (GM) Pb loadings immediately after demolition increased 200% for streets to 8080 microg/ft(2), 138% for alleys to 6020 microg/ft(2), and 26% for sidewalks to 2170 microg/ft(2). One month after demolition, the GM Pb loadings for streets, alleys, and sidewalks were reduced on average by 41-67% from post-demolition levels and were below baseline levels for alleys and sidewalks. The other main site had smaller increases in GM Pb loadings immediately after demolition-18% for alleys to 1740 microg/ft(2) and 18% for sidewalks to 2050 microg/ft(2)-and a decrease of 29% for streets to 2730 microg/ft(2). Exterior dust is a public health concern because it is a pathway of ambient Pb exposure and a potential source of residential exposure via tracking and re-aerosolization and re-deposition. Our findings highlight the need to control demolition-related Pb deposition and to educate planners, contractors, and health and housing agencies. This is particularly important given the large numbers of aging US dwellings that will be razed as part of future urban redevelopment efforts.     

中国12个城市中心城区步行道设置情况调查

目的 了解中国12个城市中心城区步行道配备、维护情况及其与城市经济水平、区域居住密度和街道繁荣程度间的关联。方法 以北京、天津、上海、青岛、杭州、绍兴、苏州、南通、镇江、成都、西宁、哈尔滨共12个城市的54个中心城区333个调查点内所有的道路为调查对象,于2012年采用观察法调查道路两侧步行道的配备及维护情况。结果 共有4 255条路段纳入分析,其中有71.1%的路段配有步行道。12个城市中配备步行道的路段比例最高的城市为青岛（91.9%）和哈尔滨（90.6%）,最低的是苏州（48.6%）和绍兴（52.6%）。12个城市在步行道配备及维护各方面差异均有统计学意义,高经济水平城市的步行道配备和路面维护情况较好、阻碍较少,但步行道隔离连续性较差、划线停车较多。相比低居住密度区域,高居住密度区域的步行道隔离连续性较差、步行道较窄,同时划线停车和阻碍较多。道路繁荣度越高,步行道配备和步行道宽度的情况越好,但隔离连续性、路面维护状况越差,划线停车和阻碍也更多。结论 12个城市步行道配备及维护状况差异具有统计学意义,12个城市步行道的配备情况还存在进一步改善的空间。建议在进行城市道路规划时,结合当地人口密度和实际的交通需求,合理配备步行道;同时加强城市管理,减少步行道上的阻碍。     

Environmental and Social Determinants of Youth Physical Activity Intensity Levels at Neighborhood Parks in Las Vegas,NV

Parks can play an important role in youth activity. This study used observational data to evaluate the relationship of environmental and social determinants to youth physical activity intensity levels in Las Vegas neighborhood parks. System for observing play and leisure activity in youth was used to code activity levels as sedentary, walking, or vigorous in five low-income and five high-income parks. Environmental determinants included amenities, incivilities, size, high-speed streets, sidewalk condition, and temperature. Social determinants included percent minority and Hispanic, gender, and income. A multinomial logistic regression model was performed. We observed 1,421 youth, 59 % male, 41 % female; 21 % were sedentary, 38 % walking, and 41 % vigorous. Males were more likely to be observed walking (OR 1.42) and vigorous (OR 2.21) when compared to sedentary. High-speed streets (OR 0.76), sidewalks condition (OR 0.34), and low-income neighborhoods (OR 0.07) was associated with decreased odds of vigorous activity; incivilities (OR 1.34) and amenities (OR 1.27) were associated with greater odds of being vigorous. Environmental and social determinants are associated with physical activity intensity levels at parks. Stakeholders should ensure quality parks, as they relate to physical activity levels in youth. Understanding environmental and social determinants that influence physical activity at parks is critical to utilizing their full potential in an effort to combat childhood obesity.     

Association between neighborhood walkability and GPS-measured walking,bicycling and vehicle time in adolescents

ObjectivesTo investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth.MethodsParticipants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups.ResultsWalking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking.ConclusionsIncreasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability.     

Relationships among community characteristics and walking and bicycling for transportation or recreation

PURPOSE: Compare walking and bicycling for transportation and recreation with the percentage of the community devoted to parklands. METHODS: Behavioral Risk Factor Surveillance System (N = 206,992), Nationwide Personal Transportation Survey (N = 409,025), and Trust for Public Land (N = 55) data were used to estimate recreational walking and bicycling, utilitarian walking and bicycling, and parkland as a percentage of city acreage. Data were linked at the metropolitan statistical area or city level (N = 34). Pearson correlation coefficients were used to assess the associations among recreational and utilitarian walking and bicycling and parkland acreage. RESULTS: Utilitarian walking and bicycling and parkland acreage were significantly correlated (r = .62, p < .0001). No significant relationships were observed for leisure time walking or bicycling. DISCUSSION: Communities with more parks had significantly higher levels of walking and bicycling for transportation. Urban design features associated with leisure time physical activity might differ from those associated with transportation-related physical activity. Further studies are needed to articulate the relationships among community attributes and purposes of physical activity.     

Speed and exercise intensity of recreational walkers

BACKGROUND: Brisk walking has been identified as an activity suited to meet American College of Sport Medicine/Centers for Disease Control and Prevention recommendations for moderate intensity exercise (55-69% HR(max), 40-59% VO(2)R). However, little is known about whether recreational walkers self-select a pace which elicits this intensity and how they interpret the term "brisk walking." METHODS: The walking speed of 82 adults was covertly observed in a public park. Fifty-nine of these participants demonstrated their interpretation of "brisk walking" and the speed was noted. Eleven of these subjects subsequently walked on a treadmill at their observed and "brisk walk" speeds. Heart rate (HR), respiratory gases, and ratings of perceived exertion (RPE) were measured. RESULTS: Mean observed and "brisk" walking speeds were 1.56 +/- 0.17 m. s(-1) and 1.79 +/- 0.19 m x s(-1) respectively (P < or = 0.001). Mean exercise intensities during the treadmill test (n = 11) were 59.0 +/- 13.4% VO(2max) and 67.3 +/- 11.6% HR(max) for the observed speed (1.60 + 0.24 m x s(-1)). The brisk speed (1.86 +/- 0.12 m x s(-1)) equated to 68.6 +/- 14.9% VO(2max) and 78.5 +/- 15.5% HR(max). CONCLUSION: The speed and intensity selected by this group of walkers meets current recommendations for moderate intensity exercise. Instructing individuals to "walk briskly" prompts more vigorous activity.     

Walking exercise and its relationship to serum lipids in Japanese

This study sought to investigate the effects of walking on serum lipids among the middle-aged and elderly. The subject group included 3312 adult Japanese who underwent a routine health examination at Yukuhashi city, Fukuoka Prefecture, in 1998. The amount of walking in which the subjects engaged and other lifestyle characteristics were examined by a self-reported questionnaire. Analyses of variance were performed to calculate adjusted means of total cholesterol, HDL cholesterol, triglyceride, and LDL cholesterol using walking time as the level of a factor. Multiple logistic regression analyses were also performed to estimate odds ratios and 95% confidence intervals for unfavorable lipid profiles. For both sexes, the adjusted mean for total and LDL cholesterol was higher in individuals who walked than in those who did not walk, and also individuals who walked had higher odds ratios for higher total cholesterol levels than those who did not walk. For men, the adjusted mean for HDL cholesterol was higher in individuals who walked than in those who did not walk. No significant difference was observed in triglyceride or the ratio of total cholesterol to HDL cholesterol between individuals who walked and those who did not walk. This suggests that walking exercise may not achieve the beneficial effect on lipids profiles among middle-aged/older Japanese.     

Policies and opportunities for physical activity in middle school environments

BACKGROUND: This study examined physical activity opportunities and barriers at 36 geographically diverse middle schools participating in the Trial of Activity for Adolescent Girls. METHODS: Principals, physical education and health education department heads, and program leaders were interviewed to assess policies and instructional practices that support physical activity. RESULTS: Schools provided approximately 110 hours per year in physical education instruction. Approximately 20% of students walked or bicycled to school. Eighty-three percent of schools offered interscholastic sports and 69% offered intramural sports. Most schools offered programs for girls, but on average, only 24 girls ( approximately 5%) in the schools attended any programs. Only 25% of schools allowed after school free play. An overall score created to assess school environmental support for physical activity indicated that, on average, schools met 6.7 items of 10 items. Free/reduced lunch program participation versus not (p = .04), perceived priority of physical education instruction over coaching (p = .02), and safety for walking/bicycling to school (p = .02) predicted environmental support score. CONCLUSIONS: Schools have policies and practices that support physical activity, although unfavorable practices exist. Schools must work with community partners and officials to provide environments that optimally support physical activity, especially schools that serve low-income students.     

Socioeconomic status differences in recreational physical activity levels and real and perceived access to a supportive physical environment

BACKGROUND: Spatial access to recreational facilities and perceptions of the neighborhood environment and physical activity levels were examined by the socioeconomic status of area of residence (SES). METHODS: A cross-sectional survey of adults (18-59 years) (n = 1,803) stratified by SES using a geographic-based index was conducted. RESULTS: Respondents in low SES areas had superior spatial access to many recreational facilities, but were less likely to use them compared with those living in high SES areas. They were more likely to perceive that they had access to sidewalks and shops, but also perceived that their neighborhood was busier with traffic, less attractive, and less supportive of walking. After adjustment, respondents living in low SES areas were 36% less likely to undertake vigorous activity. While they were more likely to walk for transport, this was not statistically significant (OR, 1.27; 95% CI, 0.98-1.64), nor were other SES differences in walking for recreation and walking as recommended. Modifiable environmental factors were associated with walking and vigorous activity, especially perceived access to sidewalks and neighborhood attractiveness. Spatial access to attractive, public open space was associated with walking. CONCLUSIONS: Creating supportive environments--particularly sidewalks in attractive neighborhoods--has the potential to increase walking and vigorous activity.     

Health locus of control and participation in physical activity

Abstract The purpose of this study was to determine the physical activity participation patterns of college students when defined by their Health Locus of Control orientation. One thousand thirty-three college-aged students completed the Wellness Activity Profile, a questionnaire that yielded data on Health Locus of Control and self-reported frequency of participation in physical activities. Discriminant analyses indicated that the combination of physical activities associated with internally and externally oriented students were different for both males and females. Participation in high caloric expenditure activities was more frequent among internal subjects (Male: bicycling, volleyball, other individual sports, and snorkel/scuba diving; Female: basketball, weight training, tennis, fast walking/jogging/running, and judo/karate), while low caloric expenditure activities were associated with an external orientation (Male: baseball/softball, sailing, fishing, golf, and other recreational sports; Female: track and field jumping and fishing).     

Environmental and lifestyle factors associated with overweight and obesity in Perth,Australia

PURPOSE: To examine associations between environmental and lifestyle factors and overweight or obesity. DESIGN: A cross-sectional survey and an environmental scan of recreational facilities. SETTING: Metropolitan Perth, Western Australia. SUBJECTS: Healthy sedentary workers and homemakers aged 18 to 59 years (n = 1803) living in areas within the top and bottom quintiles of social disadvantage. MEASURES: Four lifestyle factors, one social environmental factor, and five physical environment factors (three objectively measured). RESULTS: After adjustment for demographic factors and other variables in the model, overweight was associated with living on a highway (odds ratio [OR], 4.24; 95% confidence interval [CI], 1.62-11.09) or streets with no sidewalks or sidewalks on one side only (OR, 1.35; 95% CI, 1.03-1.78) and perceiving no paths within walking distance (OR, 1.42; 95% CI, 1.08-1.86). Poor access to four or more recreational facilities (OR, 1.68; 95% CI, 1.11-2.55) and sidewalks (OR, 1.62; 95% CI, .98-2.68) and perceiving no shop within walking distance (OR, 1.84; 95% CI, 1.01-3.36) were associated with obesity. Conversely, access to a motor vehicle all the time was negatively associated with obesity (OR, .56; 95% CI, .32-.99). Watching 3 or more hours of television daily (ORs, 1.92 and 1.85, respectively) and rating oneself as less active than others (ORs, 1.66 and 4.05, respectively) were associated with both overweight and obesity. After adjustment for individual demographic factors and all other variables in the model, socioeconomic status of area of residence and leisure-time physical activity were not associated with overweight or obesity. CONCLUSION: Factors that influence overweight and obesity appear to differ, but aspects of the physical environment may be important. Objectively measured neighborhood environment factors warrant further investigation.     

Poverty-related factors associated with obesity prevention policies in Utah secondary schools

To address the childhood obesity epidemic, numerous national agencies have outlined specific school policy recommendations for nutrition and physical activity. The extent to which current policies differ by socioeconomic status and geographic location is yet to be determined. This cross-sectional study examined select school nutrition and physical activity policies by markers for poverty among 209 middle and high schools in Utah (82% response rate). The results show that students' opportunities to establish healthful dietary and physical activity patterns differed by economic circumstances and geographic location. Schools with the highest percentage of free and reduced-price lunch enrollment and schools in rural areas were both less likely to offer a variety of healthful foods outside of the school meal program (ie, competitive foods and drinks) and intramural activities or physical activity clubs. Schools with highest free and reduced-price lunch enrollment were more likely to allow the purchase of unhealthful snacks during lunchtimes than schools with low enrollment (28.4% vs 7.6%, P=0.01). Schools in rural communities were less likely to promote walking and bicycling to school compared with other locations (47.4% rural vs 67.1% urban and 63.6% suburban, P=0.06). Current school policies related to nutrition and physical activity may not be conducive to reducing the childhood overweight problem among children attending schools in areas with increased risk factors due to poverty or rural location in Utah.     

Physical activity and cardiovascular disease risk in middle-aged and older women.

The authors investigated the relation between physical activity and cardiovascular disease (CVD) in women by following 1,564 University of Pennsylvania alumnae (mean age, 45.5 years), initially free of CVD, from 1962 until 1993. Energy expenditure was estimated from the daily number of flights of stairs climbed and blocks walked as well as the sports played and was categorized into approximate thirds (<500, 500-999, > or = 1,000 kcal/week). During 35,021 person-years, 181 CVD cases were identified. After adjustment for coronary risk factors, the relative risks of CVD were 0.99 (95% confidence interval (CI): 0.69, 1.41) and 0.88 (95% CI: 0.62, 1.25) for women who expended 500-999 and > or = 1,000, respectively, compared with <500 kcal/week (p for trend = 0.45). Only walking was found to be inversely related to CVD risk (p for trend = 0.054). Compared with women who walked <4 blocks/day, the relative risks of CVD were 0.84 (95% CI: 0.59, 1.19) and 0.67 (95% CI: 0.45, 1.01) for women who walked 4-9 and > or = 10 blocks/day, respectively. Finally, an interaction (p = 0.023) between body mass index and physical activity on CVD risk was observed, with an inverse association only for leaner (<23 kg/m2) women. These data showed no overall association of physical activity with CVD risk in women. However, walking > or = 10 blocks/day (approximately 6 miles (9.7 km)/week) was associated with a 33% decreased risk. One explanation for this finding may be that walking was reported more precisely than other kinds of activities.