The purpose of this project is to examine the lifestyle physical activity behaviors and the determinants/correlates of physical activity, including background (acculturation, discrimination and environment) and intrapersonal (self-efficacy) characteristics in midlife South Asian Indian (SAI) immigrants at risk for cardiovascular disease, diabetes, and central obesity. The study aims are to: (1) identify the lifestyle physical activity behavior (leisure time, occupational and household) of SAI immigrants;(2) examine the mediating effects of the dynamic intrapersonal characteristic (self-efficacy for overcoming barriers to lifestyle physical activity) on the relationship between the static background characteristics and lifestyle physical activity behavior in SAI immigrants, controlling for demographics, current health and social support. This study will address the Healthy People 2010 objective of increasing from 15% to 30% the percentage of Asian adults engaging in moderate physical activity and the National Institute of Nursing Research emphasis on the elimination of health disparities. Guided by the Physical Activity Behavior Framework for SAI Immigrants (based on social cognitive theory and the ecological model), the study design is a cross-sectional, descriptive, face-to-face interview survey. Inclusion criteria are SAI immigrant men and women born in India and immigrated to the U.S., 40 to 65 years of age, without physical activity disability. A sample of 110 men and women will be recruited through SAI religious institutions, businesses, newspapers, and word of mouth. Physical activity will be assessed by self-report (Community Healthy Activity Model Program for Seniors [CHAMPS] for leisure and household, Tecumseh Occupational Activity Instrument for occupational) and weekly steps and minutes in moderate/high-intensity activity registered on an accelerometer. Additional measures include acculturation, discrimination, environment (sense of community), self-efficacy for physical activity, global health, and Center for Epidemiological Studies-Depression scale (CES-D) scores. Translation of measures was done by the committee method, followed by focus groups. Think-aloud interviews were conducted to assure cross-cultural relevance. Participants will wear the accelerometer for one week and return it via mail. Descriptive statistics will be obtained for all measures and by gender. The data analysis will be based on the mediating regression model. The model will be used to explain the influence of self-efficacy on the relationship between background characteristics (acculturation, discrimination and environment) and physical activity. Findings will provide guidance in developing culturally relevant strategies for increasing physical activity and decreasing health disparities in SAIs. PUBLIC HEALTH RELEVANCE: The serious health disparities associated with higher risk for cardiovascular disease (CVD), diabetes mellitus and central obesity and lower levels of physical activity in South Asian Indian immigrants residing in western countries compared to Caucasians is a major public health concern. This research will be among the first to identify the influence of acculturation, discrimination and environmental factors on the physical activity behavior and health of this vulnerable immigrant population. Findings will be used to develop tailored and targeted interventions.