South Asians (SAs) make up a quarter of the world's population and are one of the fastest growing racial/ethnic minority groups in the United States (U.S.). Our data, and others, have found that SAs are some of the least physically active adults in the U.S. and may require special considerations when designing and implementing PA programs. SAs also manifest greater visceral adiposity, insulin resistance, and a significantly higher prevalence of DM, at a lower BMI, compared to other racial/ethnic groups. Regular PA has been shown to decrease visceral adiposity, improve insulin sensitivity, and prevent DM, even in the absence of weight loss; thus, PA may be especially important to prevent or delay the onset of DM in SA populations. Facilitating and promoting PA interventions for the growing SA population could lead to a substantial impact on their DM risk. Yet there is almost no research on how best to adapt evidence-based PA interventions for U.S. SAs. Our prior community-based participatory research, conducted in SA communities with a high proportion of recent immigrants who have limited English proficiency and limited access to health care, found that SA women, in particular, are not being reached by current PA interventions. SA women reported little PA and even had difficulty defining exercise. Although 75% of the women were sedentary and overweight/obese, they did not recognize these as risk factors for DM. Lack of knowledge about benefits of PA, cultural and linguistic isolation, concerns about modesty, and rigid gender roles were strongly influencing SA women's PA. Despite these barriers, SA women were willing to participate in exercise if it could be done in women-only classes, with their children, and in a trusted community setting. In partnership with Chicago's SA community, we used this formative data, community input, and a social determinants framework, to develop an innovative PA intervention. The intervention includes community-based exercise classes that engage SA women and their children in moderate intensity aerobic PA and resistance exercises through culturally-acceptable activities. During the proposed 2 year-study, we will work with community partners to pilot-test healthcare-based identification of SA women at high risk for developing DM followed by delivery of a culturally-salient PA intervention in a community-based setting, via a 2-arm randomized design, and examine the intervention's feasibility (recruitment, retention, and program adherence) and initially efficacy on HbA1c. Secondary outcomes are fasting plasma glucose; biomarkers associated with insulin resistance; components of the metabolic syndrome; PA; and psychosocial processes. A process evaluation will be used to understand participants' and interventionists' perceptions of the intervention and its implementation. Study results will provide essential data for planning a larger-scale efficacy trial to reduce DM risk in SAs via community-based PA interventions. Importantly, the proposed study's community-participatory approach will use a fundamental structure that is generalizable and could be replicated in other high-risk, vulnerable populations. .