From Pacers: "Join Pacers Running Stores for complimentary fun runs in the mornings and evenings across the greater Washington DC area. Runs range from 3-7 miles (unless otherwise noted) all paces welcome. Most listed runs are free (unless otherwise noted) and open to the public. All you have to do is just show up and be ready to run!"
Visit the Pacer's Website link below for more details and contact information. Contact the host for the length of the run.