Even the author of that research paper that that book is based on doesn't run marathons barefoot. He said humans aren't meant to run 26.2 miles nonstop barefooted.
It is believed to be one of the oldest hunting techniques, and so would indicate that humans are in fact meant to run long distances. According to Wikepedia, the runner runs for "about two to five hours over 25 to 35 km (16 to 22 mi)".
For sure. And that's the point. Persistence hunting is a strategy developed by a set of humans living in one small area of the world that isn't particularly hospitable to humans. In fact, give how inhospitable the African Savannah is, it is a point against the idea that this is somehow a 'natural' state of being for us. And it makes sense, this kind of long distance running is incredibly energy intensive and injury prone - it's not a great way to make a living.
It is believed to be one of the oldest hunting techniques, and so would indicate that humans are in fact meant to run long distances. According to Wikepedia, the runner runs for "about two to five hours over 25 to 35 km (16 to 22 mi)".