I don't know why this made such a huge impression on me when I first read it, but it did.
"Running is a high impact sport."
My initial response, even as a physical therapist (*gasp!*) was"Are you sure about that?"
Because my mind went straight to literal impact sports.
You get it.
So I stewed on it.
And then, the lightbulb.
Oh my goodness, it IS a high impact sport.
What threw me was that running doesn't fit the traditional definition of high impact where we traditionally think of "contact sports". And in the context of a "contact sport" we think of tackling or other physical contact between players.
Where I went wrong was misunderstanding "high impact" for "contact".
And all along I knew that strength training was a must for runners!