BACKGROUND
Over the past decade there has been increasing recognition of the role of the built environment in influencing physical activity (PA). The impact of the built environment on PA at the neighborhood scale is even more important for disadvantaged groups since they are less likely to have the resources to access amenities like parks/gyms outside their neighborhoods, while their own neighborhoods are likely to have fewer free-for-use resources. Moreover, minority groups, especially minority women bear a significantly higher risk of obesity-related illnesses while being traditionally under-represented in research. The primary focus of this exploratory study is to further understanding of the role of PA in the lives of adult women living in public housing in Harrisburg, PA.

OBJECTIVES
The goals of this study are to: 1) explore the role of PA in the lives of female public housing residents and identify perceived barriers to PA, and 2) investigate the reliability/efficiency of collecting objective and subjective measures of physical activity data for this population. A related objective of this study is to examine the relationship between physical activity status of the study participants and the built environment. However, it is recognized that the small number of planned study participants (75 - 100), might not allow for the comprehensive investigation of this relationship.

METHODS
Participants for the study were solicited through kick-off meetings at three family public housing sites in Harrisburg, PA: 1) Hall Manor, 2) Hoverter Homes, and 3) the cluster of Smith/Howard Day/ Hillside Village. Participants were trained to use pedometers, and fill out pedometer activity logs. Objective physical activity data was collected through pedometer activity logs for 7 consecutive days, and subjective physical activity data was collected through the International Physical Activity Questionnaire (short-form) in a face-to-face interview format for the same seven day period, allowing for the comparison of the two physical activity data sets. Basic demographic data was collected through face-to-face interviews, while focus group sessions were used to gather information on the role of physical activity in their daily lives, and perceived barriers to physical activity. The Irvine Minnesota Inventory with minor modifications was used to conduct environmental audit of the neighborhood around each public housing site.

The study is ongoing, and data collection will be completed by September 2006. To date complete PA data has been collected from 18, 35, and 20 participants at Hall Manor, Hoverter Homes, and Smith/Howard Day/Hillside Village respectively. Environmental audit (using a modified version of the Irvine-Minnesota Inventory) of the Smith/Howard Day/Hillside Village neighborhood has been completed, while that of Hall Manor and Hoverter Homes neighborhoods is ongoing and will be completed in August, 2006. Focus group sessions have been conducted at the three sites.

RESULTS
Role of PA
Study participants were aware of the health benefits of physical activity, but were unable to maintain a regular schedule of physical activity. The lifestyle of most residents can be characterized as fraught with difficulties and lacking routine, problematizing the incorporation of regular physical activity into their daily lives.

Perceived barriers to PA
Fear of crime emerged as the most important barrier to physical activity. Other consistent themes that surfaced from focus group sessions were: 1) lack of organized activity for youth and adults, 2) absence of no-fee recreational facilities within walking distance, and 3) absence of destinations like parks and grocery stores in the neighborhood.

Comparison of subjective and objective PA data
Of the 84 study participants, 67 turned in pedometer activity logs and responded to the IPAQ questionnaire. Of these 67, 52 (78%) pedometer logs yielded valid pedometer generated PA data. Consistent with the literature, self-reported IPAQ measures of physical activity are higher than those generated through pedometer logs. According to IPAQ, 4.5% of respondents were inactive, while according to Tudor-Locke et al (2004) classification of pedometer data, 44% of respondents were sedentary. There were only 9 (or about 17%) matches between IPAQ and pedometer activity log data.

CONCLUSIONS
The high rate of discrepancy between self-reported and pedometer generated data calls into question studies that rely on self-reported measures of PA with reference to this population. The low levels of PA reported through pedometer generated data suggests room for improvement in the physical activity status of female public housing residents. Evidence from this exploratory study suggests that policies that target crime reduction at the neighborhood level, and promote PA programming for adults/youth may help to increase the activity levels of public housing residents. Future studies are needed to investigate this line of reasoning.