Home-Based Measures of Physical Activity and Body Composition

The specific aim of this study is to collect preliminary data on the feasibility and validity of home-based data collection methods to measure four constructs: * Physical Activity: Real-time assessment using Ecological Momentary Assessment (EMA) and pedometers * Cardiorespiratory Fitness: Step test * Anthropometry: Waist and hip circumference measurements * Environmental Variables: Examples include density of neighborhood physical activity facilities (including gyms, parks, walking trails), crime, land use mix, and transportation variables, collected by participants using EMA.