I hear distance runners refer to running endurance or stamina. And of course, there's always speed. But occasionally you hear runners mention "strength" as a runner as if it's an aspect separate from speed or endurance.
For example, Kara Goucher said she's "slower but stronger than I was in 2009," and she believes that on April 17, "when I hit the 20-mile mark in Boston, I know I’ll be glad that Alberto (Salazar, her coach) had me focus on strength."
How can you be slower but stronger as a runner? How is "strength" as a runner different than speed or endurance?
(And no, I'm not at all trying to critique Kara for this remark. I'm all for Kara and hope she does great in her upcoming races. I'm just curious about this terminology, and she's not the only one that uses it, but it reminded me when I saw it in her remarks today.)