According to Sisson, prolonged high heart rate are bad for the body, and he makes the statement that humans didn't evolve to run long distances
Dear Mark: Chronic Cardio | Mark's Daily Apple
The fact is, our hunter-gatherer ancestors didnít ramp up their heart rates significantly for over an hour every day, and I donít think we should either. They walked at a very low level of exertion, burning almost entirely stored fats.
Chris McDougall seems to be asserting the complete opposite point in his book, and the video below. The truth does seem to lean towards Chris. If we weren't meant to run such long distances, why are we so much better at it than any other animal on the planet? I also think that it's pretty undeniable that humans used persistence hunting as their main form of survival for years.

So, which is right?