Iñigo San Millán, Ph.D.: Zone 2 Training and Metabolic Health (Ep. #85 Rebroadcast)

Today's episode of The Drive is a rebroadcast of the conversation with Iñigo San Millán, (released on December 23rd, 2019). This episode with Iñigo was one of the most popular discussions to date and is a prelude to an upcoming follow-up discussion in 2022. In this episode, Dr. Iñigo San Millán, Assistant Professor at the University of Colorado School of Medicine, explains the crucial role of mitochondrial function in everything from metabolic health to elite exercise performance. Iñigo provides a masterclass into the many different energy system pathways, the various fuel sources (including the misunderstood lactate), the six zones of exercise training, and the parameters he uses to measure metabolic health. Additionally, he highlights the power of zone 2 training as both an effective diagnostic tool and, perhaps more importantly, as a treatment for mitochondrial and metabolic dysfunction. We discuss: Iñigo's background in sports and decision to focus on education [3:45]; The various energy systems and fuels used during exercise [11:15]; Iñigo's qualification of energy systems into six training zones [19:30]; Lactate as an important fuel source [29:30]; Zone 2 training—physiologic characteristics, fuel sources, lactate, and the transition into zone 3 [37:00]; Using blood lactate levels (and zone-2 threshold) to assess mitochondrial function [43:30]; Accessing mitochondrial function by testing one's ability to utilize fat as fuel [51:30]; Athletes vs. metabolically ill patients—mitochondria, fat oxidation, muscle glycogen capacity, "fat droplets", and more [56:30]; Physiologic characteristics of zone 3, zone 4, and the lactate threshold [1:16:30]; Fueling exercise—dietary implications on glycolytic function [1:27:00]; Relationship between exercise and insulin sensitivity (and what we can learn from studying patients with type 1 diabetes) [1:43:00]; Metformin's impact on mitochondrial function, lactate production, and how this affects the benefits of exercise [2:00:45]; Raising awareness of the risk of "double diabetes" [2:11:30]; How to dose zone 2 training, and balancing exercise with nutrition [2:14:30]; Proposed explanation of the Warburg Effect: Role of lactate in carcinogenesis [2:23:30]; Doping in cycling, and the trend towards altitude training [2:35:45] and; More. View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Learn More About Peter Attia Sign Up to Receive Peter's Weekly Newsletter Connect With Peter on Twitter, Instagram, Facebook & YouTube