The Limits of Human Energy Expenditure with Herman Pontzer PhD and Drew Best PhD | Koopcast Episode 157
Episode overview:
Herman is a professor of evolutionary anthropology at Duke University, where he focuses on the evolution of human energy expenditure and metabolism. He is also the co-founder of the Human Evolutionary Ecology Lab, where he and his team study the effects of diet, physical activity, and modern environments on human health and disease.
Herman’s latest book, "Burn: The Misunderstood Science of Metabolism," explores the latest research on metabolism and challenges long-held beliefs about weight loss and metabolism. His work has been featured in numerous publications and media outlets, including The New York Times, The Wall Street Journal, and NPR
Andrew Best is a biological anthropologist and Assistant Professor of Biology at the Massachusetts College of Liberal Arts; he is also a respectable endurance athlete in his own right. Ancdrew is currently conducting a research project on ultramarathon and ultra endurance athletes that further tests the limits of the human metabolic scope.
Episode highlights:
(15:23) The hypothesis: when you exercise you expend less energy to inflammation, stress, hormone regulation
(25:18) Reevaluating performance: energy expenditure may be the limiting factor in ultramarathons, if so training can be structured to target metabolic scope
(51:37) Training applications: strategically exceeding your metabolic ceiling during important moments in training and repaying metabolic debt when it matters least
Our conversation:
(0:00) Intro: introducing Herman Pontzer, Andrew Best, and the research study
(2:44) Discussing Herman’s books: individual physiology from an evolutionary lens, current project, Burn
(5:05) Introducing Drew: sweat evolution, endurance physiology, Joe McCounahay
(7:27) Why endurance is important to evolutionary biology: metabolism is where the body applies its functions
(9:00) Studying hunter-gatherers, lifestyle and exercise changes the method of energy expenditure but not total expenditure, investigating metabolic limits
(12:50) Overview of metabolism: basal metabolism, movement, thermoregulation, stress, circadian changes
(15:23) The hypothesis: when you exercise you expend less energy to inflammation, stress, hormone regulation
(17:51) Exercise is not a tool for weight loss: your metabolism adjusts to your lifestyle
(19:07) Research setup and physiological background : BMR, duration versus sustainable metabolic scope
(21:28) Why study ultrarunners: maximal energy expenditure over days, caveats
(23:17) Metabolic ceiling examples: ultramarathons, Tour de France, running across the U.S., pregnancy
(25:18) Reevaluating performance: energy expenditure may be the limiting factor in ultramarathons, if so training can be structured to target metabolic scope
(27:52) Study setup: double-labeled water experiment, metabolic data from urine samples, recruiting ultrarunners
(31:01) Proposed metabolic ceiling: finding the limits of human energy expenditure by trying to break them
(32:46) Theoretical metabolic ceiling: ~2.5x BMR per year, methods of calculating metabolic scope
(35:38) Doing more with less: potential training implications of metabolic scope, discrepancies in the data set
(37:40) Predicting overtraining: prolonged energy expenditure over 2.5x BMR may lead to RED-S
(39:49) Koop’s takeaway: you can exceed your metabolic ceiling in the short term but not in the long term
(40:36) Examples of 2.5x BMR: practicality, caveats, approximately 25-35 miles of flat running for a typical male
(44:06) Herman on exceeding 2.5x BMR: athletes who claim exception are likely misreporting training, balancing out metabolic debt
(45:41) Drew on exceeding 2.5x BMR: metabolic debt, human variation, digestion as a potential limiting factor, metabolic compensation
(50:22) Jason’s data: 2.6x BMR, other athletes with more training and lower metabolic scope, applications for human evolution and ultra endurance training
(51:37) Training applications: strategically exceeding your metabolic ceiling during important moments in training and repaying metabolic debt when it matters least
(53:32) Recruiting athletes: Herman’s study on female athletes and pregnancy
(55:50) Recruiting athletes: finding high-volume athletes to investigate the theorized metabolic ceiling
(57:40) Wrap-up: giving thanks, Herman’s new book “Burn”
(58:18) Outro: giving thanks, sharing the KoopCast
Additional resources:
Contact for Andrew-
Website: www.therunningprimate.com
Instagram: @therunningprimate
Twitter: @RunningPrimate
Strava: The Shreddy Professor
Buy Training Essentials for Ultrarunning on Amazon or Audible
Information on coaching-
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