Physical inactivity and obesity significantly increase the risk of colon, breast, endometrial, pancreatic, lung, and other types of cancer. However, 40% of U.S. adults report no leisure-time physical activity, and 66% of adults are overweight or obese, with these rates even higher in Hispanic and low SES populations. Evidence suggests that 30-60 minutes of moderate to vigorous intensity physical activity per day can reduce cancer risk, and weight maintenance and loss require up to 60 minutes per day. Health benefits can be achieved when the total duration of physical activity is accumulated across multiple bouts lasting at least 10 minutes each. Thus, promoting multiple brief physical activity episodes is a promising strategy to reduce cancer risk. However, information about factors influencing decisions to engage in physical activity bouts across the day is severely lacking. The proposed study will investigate how time-varying factors (e.g., cognitions, mood, and physiological sensations) predict subsequent physical activity levels throughout the day. It will also consider how neighborhood built environmental characteristics (e.g., walkability, mixed land use, access to destinations, open space) influence and/or interact with these decision-making processes.

This project used an innovative research methodology, Ecological Momentary Assessment (EMA) with mobile phones, to capture real-time in situ data from low- and middle-income ethnically diverse adults (44% Hispanic). Participants consisted of (1) individuals moving to a smart growth community in Southern California (with walkable neighborhoods, mixed land use, and preservation of open space) (n = 55) and (2) individuals living in surrounding traditionally-designed comparison communities (n = 55).

Electronic EMA occurred across four consecutive days (Fri-Mon) with 7 randomly programmed data recording prompts per day. Each EMA wave occurred at 0-3 months, 6-9 months, and 12-15 months post-move for the smart growth group and equivalent time intervals for the comparison group. Accelerometers measured physical activity, and Body Mass Index (BMI) was determined from height and weight assessed by stadiometer and scale.