Successful distance running draws on many traits. Speed is a gift from our parents. Physical strength helps, as do leanness of the body and efficiency of movement. Mental strength – sometimes defined as a 'high pain threshold' – plays a big role, as does a strong motivation to succeed. But no trait better defines a distance runner or is admired by runners than endurance. This is the ability to persist, to go the distance, and come back for thousands of tomorrows. The best one-line statement ever written about distance running didn't come from a coach or author. It came from an anonymous ad writer for the Nike shoe company, who coined the phrase 'there is no finish line.' As a runner, you aren't looking for places to stop but for ways to keep going. You greatest victory doesn't come at the end of any race but in running that never ends.