 Pedometers. Walking is a practical way to achieve physical activity recommendations among individuals experiencing homelessness, as it does not require any specific equipment and may be a common activity and means of transportation in this population. Pedometers are small and inexpensive devices that measure steps walked per day. All study participants will be provided with a New Lifestyles NL-1000 pedometer accelerometer, which measures steps, distance, and activity minutes and is equipped with a 7-day memory and clock. Those randomly assigned to the intervention will be instructed to aim for 10,000 steps per day, but to focus on gradually increasing their steps each day rather than achieving 10,000 steps right away if they are currently very sedentary. In addition, intervention participants will be provided with information about the Back on My Feet program, which is offered at the Bridge shelter. Program members meet for a group runwalk 3 times per week on Monday, Wednesday, and Friday mornings. Intervention participants will be instructed to wear their pedometer during waking hours each day, and asked to return each week over a 4-week period 4 visits total so that study staff may record the daily step counts. We will additionally ask participants to return for a 4-week post-intervention follow-up we will remind participants to wear their pedometer the week prior to the assessment. Individuals assigned to the control group will provided with a pedometer and step goals after the final follow-up visit. All participants may keep their pedometer after their participation in the study is completed. Note that intervention and control group participants will be provided with accelerometers at the beginning of the study to provide an objective measure of physical activity. 