The new effort to get Americans of all ages moving.
Last month, we introduced you to Demian, a Brooklyn 8-year-old who enrolled in his school's chapter of the Mighty Milers, the New York Road Runners' youth program.
Yesterday, he appeared on our Weekend Today in New York morning show to support National Running Day, happening June 1.
The campaign encourages runners to share why they're so passionate about the sport and connect with one another.
In Demian's case, he says, "I like to run because it keeps me healthy."
Runners can celebrate in a number of ways, including making a "I Run..." statement and posting it; supporting charities through the sport; finding or setting up a group run on June 1; and getting tips to support friends who want to become runners.
To learn how to do all that, log on to runningday.org. Visitors will also be able to win prizes, says NYRR.
While you're at it, tell us here how you plan to celebrate!