Sign up to receive Peter's email newsletter: https://bit.ly/4c602k2 Layne Norton is a physique coach, a natural professional bodybuilder and powerlifter, and holds a Ph.D. in nutritional sciences. In this episode, Layne explains how he became interested in weightlifting and fitness both professional and academically. He provides insights into preventing and managing injuries while using consistency and determination to boost his professional success in bodybuilding and powerlifting. Peter and Layne also review the science of body composition and what’s really driving muscle growth, including the role of nutrition, supplements, and a number of important and misunderstood hormones important to muscle protein synthesis. Furthermore, Layne stresses the importance of maintaining muscle mass even while losing fat for improving metabolic health and longevity and provides the keys to developing healthy habits. We discuss: 00:00:00 - Intro 00:00:09 - Layne’s childhood and why he gravitated towards weightlifting and bodybuilding 00:10:25 - Layne’s academic path, overcoming ADHD, and kicking Adderall 00:21:35 - Paradoxical observations about expertise, and Layne’s career transition to health and fitness 00:33:05 - The power of persistence and resilience in the face of setbacks 00:45:00 - Battling injuries, managing back pain, and setting lifting records 01:01:20 - Bodybuilding vs. powerlifting: comparing and contrasting the training approaches 01:10:45 - Cutting weight without losing muscle mass: exercise and dietary protocols, fasting, and a look at the literature 01:31:35 - Muscle protein synthesis and the importance of leucine 01:44:12 - Nitrogen balance and muscle protein synthesis, and the regulatory role of hormones for fat flux and muscle growth 01:54:13 - What’s really driving muscle growth: intrinsic vs. systemic factors, IGF, and hormone signaling 02:03:45 - The role of protein, carbohydrates and insulin on muscle growth and preservation, and the importance of context when interpreting study results 02:16:53 - Clarifying the role of cortisol—a misunderstood hormone 02:24:30 - The problem with studies trying to isolate one nutrient 02:29:05 - The important role of inflammation from exercise 02:33:47 - Keys to preserving muscle, and the value of habits, consistency, and resilience Show notes page: https://peterattiamd.com/laynenorton/ -------- About: The Peter Attia Drive is a weekly, ultra-deep-dive podcast focusing on maximizing health, longevity, critical thinking…and a few other things. With over 30 million episodes downloaded, it features topics including fasting, ketosis, Alzheimer’s disease, cancer, mental health, and much more. Peter is a physician focusing on the applied science of longevity. His practice deals extensively with nutritional interventions, exercise physiology, sleep physiology, emotional and mental health, and pharmacology to increase lifespan (delay the onset of chronic disease), while simultaneously improving healthspan (quality of life). Learn more: https://peterattiamd.com Subscribe to receive exclusive subscriber-only content: https://peterattiamd.com/subscribe Sign up to receive Peter's email newsletter: https://peterattiamd.com/newsletter Connect with Peter on: Facebook: http://bit.ly/PeterAttiaMDFB Twitter: http://bit.ly/PeterAttiaMDTW Instagram: http://bit.ly/PeterAttiaMDIG Subscribe to The Drive: Apple Podcast: http://bit.ly/TheDriveApplePodcasts Overcast: http://bit.ly/TheDriveOvercast Spotify: http://bit.ly/TheDriveSpotify Google Podcasts: http://bit.ly/TheDriveGoogle