Mark Sisson departs from the usual Primal Blueprint lifestyle topics for an interesting discussion with Brad Kearns about human fitness. For starters, Mark discussed the recent Outside Magazine article "How Far Fitness Has Fallen". Researchers claim that our hunter-gatherer ancestors, and even early farming ancestors, were far fitter than modern humans.

While it's granted that the average citizen today is soft compared to primal humans, Mark takes exception to the scientist's conjecture that, “Even our most highly trained athletes pale in comparison to these ancestors of ours." While hunter-gathers were likely excellent general physical specimens well-adapted to challenging primal life, it's ludicrous to imagine any of them competing in the specialized endeavors of today's Olympic sprinters, or marathon runners, NFL athletes. "It's hard to imagine Grok dunking over Kevin Durant".

Mark then comments on the work of Tim Noakes, PhD, a South African considered by many to be the world's leading exercise physiologist and author of the acclaimed Lore of Running. Noakes is a recent devotee of the Primal Blueprint, a lifestyle transformation that has caused him to rethink his life's work in the carb-paradigm of mainstream exercise physiology (and take a ton of heat in the process from colleagues wedded to status quo thinking).

Mark also comments extensively on Noakes's mind-blowing Central Governor Theory, which suggests that our brains are the true regulators of peak performance, in contrast to the long-held belief that performance is limited peripherally – that is by the fatiguing of the arm muscles on your final rep or your legs getting tired at the end of the marathon. Mark's takeaway message is that while we can respect our "mind over matter" powers, we must take care to balance stress and rest in a modern world that is devoid to life or death peak performance challenges.