This is a behavioral study that will examine changes in physical activity and vascular health
in response to a digital tool (app) that will appear on participant's lock screen of their
Android phone. Participants will be asked to use this app for 3 months and to wear a Fitbit
device continuously throughout the study. Participants will be asked to complete
questionnaires, participate in fitness testing and measures of cardiovascular health at 3
months and 6 months after baseline assessments. The hypothesis is that exposure to the app
will lead to increased physical activity volume and improved microvessel function.