I don't know if I buy this at all. The average woman certainly doesn't look "designed to run" to me. Have you ever tried running with a baby on your hip? I have - it ain't pretty.
If we're design to run, why do all the runners I know have blown out knees? And why would our ancestors run after game (practically all of which is faster than we are)? Wouldn't traps and ambushes be more effective?
I've been fortunate in that I've never had bad knees from running. I just hope they don't collapse this weekend when I do a 20 miler.
The first thing I thought of when reading this is the primitive societies in the Amazon rain forest and the Kalahari Desert (the latter being the !Kung people). In those societies the only "runners" are the men -- the women stay in the villages while the men hunt. Attributes in favor of running capability would be genetically favored even if the women didn't run much.
Look at how tribes like the Bushmen hunt. They chase an animal. It runs away. They follow and chase it some more. It runs away again. Do that for a few miles and it collapses from heat exhaustion because humans are among the best at getting rid of heat from the body. (of course sitting in a deer blind with some beer is a lot easier).
Well put. Humans also mimicked existing predators, doing the creep-up-on from downwind. Some prey species also have limited territories, making it possible to get them cornered. In North America there's the old kill site, "Head Bashed In" (translation) I think in western Canada, where herds were herded into a sort of funnel and over a cliff. Techniques were more important than long distance running. Probably the only role LDR played was in flight from danger -- and most of that danger was probably other humans, since (as you note) many animals outrun us.