Mark Sisson, 72 and still shredded, returns to Peak Human for a powerful conversation on what real healthspan looks like — not chasing 180 years with futuristic tech, but thriving into your 90s with energy, strength, and vitality. As the founder of the Primal Blueprint, Mark brings decades of wisdom on metabolic flexibility, minimalist training, and practical ancestral living.

In this episode, Brian and Mark discuss how to optimize metabolism, how to train smarter (not harder), the real deal with fiber, alcohol, hydration, and carbs — and why metabolic flexibility is the key to enjoying life without strict rules, guilt, or orthorexia.