Zone 2 Pioneer Dr. Iñigo San Millán: The Science of Mitochondria, Aging & Metabolic Health | #167

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I sat down with Dr. Iñigo San Millán, one of the world's leading researchers in cellular metabolism and mitochondrial function and the scientist whose methods I use every day in my practice, to decode the real science of Zone 2, lactate, and why your mitochondria are the engine of your entire health span.

What we explore: - Lactate threshold testing measures mitochondrial function, metabolic health and flexibility - Zone 2 and sprint intervals optimize VO2 max, glycolytic capacity, and healthy aging. - Elevated resting lactate signals mitochondrial dysfunction and insulin resistance - The astrocyte-neuron lactate shuttle links brain metabolism, cognitive decline, and Alzheimer's disease. - Skeletal muscle governs glucose metabolism, insulin sensitivity, and the origin of insulin resistance. - Mitochondrial decline and bioenergetic dysfunction silently precede type 2 diabetes in sedentary individuals. - Metabolic dysfunction and insulin resistance are reversible at any age through Zone 2 training and structured exercise.

About Dr. Iñigo San Millán: Dr. Iñigo San Millán is an exercise physiologist and researcher at the University of Colorado School of Medicine whose work on mitochondrial function and cellular metabolism has shaped how both elite athletes and everyday people train for health and longevity. He is best known for pioneering the science of Zone 2 training and coaching Tour de France champion Tadej Pogačar.

Connect with Dr. Iñigo San Millán: Instagram: https://www.instagram.com/inigosanmillan/

Timestamps

00:00 Intro 03:58 Lactate Testing: Your Mitochondrial Stress Test 05:38 Why Lactate Is Fuel, Not the Enemy 12:07 Zone 2 Training: What the Science Actually Shows 15:39 Why Elite Athletes Train Slow to Perform Fast 19:40 Zone 2 Gets Harder as Your Fitness Improves 24:29 Why Sprint Intervals Are Non-Negotiable 31:10 Your Brain Prefers Lactate Over Glucose 33:00 The CGM for Lactate: How Close Are We? 36:54 Why Skeletal Muscle Is Your Longevity Organ 40:53 Estrogen, Brain Energy, and Alzheimer's Risk 46:10 Are Children Missing a Critical Metabolic Window? 50:11 The Inside-Out Hypothesis: Hidden Metabolic Decline 52:48 It's Never Too Late to Reverse Metabolic Disease

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