Now I'll have to find something else to blame for my glacial running speed

Lactic Acid Is Not Muscles' Foe, It's Fuel - New York Times

At the end of the article is a passage that should delight those who celebrate irony,

Yet, Dr. Brooks said, even though coaches often believed in the myth of the
lactic acid threshold, they ended up training athletes in the best way
possible
to increase their mitochondria. "Coaches have understood
things the scientists didn't," he said.

So don't hate the lactic acid pooling in your muscles, embrace it for the fuel that it is.