#32 - Carbohydrate metabolism during exercise with Dr Mark Hargreaves

Dr Glenn McConell chats with Professor Mark Hargreaves from the University of Melbourne in Australia. He is a leader in exercise metabolism/physiology and was Glenn’s PhD supervisor. The discussion centred around the effects of muscle glycogen availability and carbohydrate (CHO) ingestion on exercise metabolism and also performance/fatigue. There was also discussion of  high fat/ketogenic diets, GLUT-4, the central nervous system and the effect of the volume of fluid ingested with and without addition of electrolytes. 0:00. Introduction and Mark’s beginnings in exercise research 9:10. Effect of exercise intensity on the fuel mix used 12:27. High fat/keto diets and exercise metabolism/performance 16:10. Hazards of too much fat or too much carbohydrate Also, what type of dietary fat and what type of dietary carbohydrate matters. 18:40. Need personalized management of people 21:05. Hard to keep muscle glycogen low 24:32. Continuous glucose monitors 25:30. Why use more glycogen during ex than need if start high? 27:00. Heat and glycogen metabolism 28:26. Why fatigue when consuming carbohydrate during ex? 31:50. Carbohydrate ingestion and liver glucose output 33:30. High doses of carbohydrate ingestion during exercise 38:00. Need increased CHO availability if ex less than an hour? 41:25. Repeated sprints and glycogen etc 43:05. Resynthesis of glycogen during low intensity exercise? 47:12. Both excess CHO and excess fat can cause problems 52:35. Caffeine vs coffee and metabolism 53:40. Rehydration with meals vs special solutions 54:25. Fluid ingestion and electrolytes 59:10. Glycogen and AMP-activated protein kinase (AMPK) 1:00:50. Mark’s current senior academic position 1:02:47. Mark’s “photographic memory” and the literature 1:04:39. Exercise and GLUT-4 expression 1:09:00. Muscle GLUT-4 normal in muscle in T2D 1:10:23. Takeaway messages 1:14:34. Outro (9 secs) Inside Exercise brings to you the who's who of research in exercise metabolism, exercise physiology and exercise’s effects on health. With scientific rigor, these researchers discuss popular exercise topics while providing practical strategies for all. The interviewer, Emeritus Professor Glenn McConell, has an international research profile following 30 years of Exercise Metabolism research experience while at The University of Melbourne, Ball State University, Monash University, the University of Copenhagen and Victoria University. He has published over 120 peer reviewed journal articles and recently edited an Exercise Metabolism eBook written by world experts on 17 different topics (https://link.springer.com/book/10.1007/978-3-030-94305-9). Connect with Inside Exercise and Glenn McConell at: Twitter: @Inside_exercise and @GlennMcConell1 Instagram: insideexercise Facebook: Glenn McConell LinkedIn: Glenn McConell https://www.linkedin.com/in/glenn-mcconell-83475460 ResearchGate: Glenn McConell Email: [email protected] Subscribe to Inside exercise: Spotify: https://open.spotify.com/show/3pSYnNSXDkNLH8rImzotgP?si=Whw_ThaERF6iIKwxutDoNA Apple Podcasts: https://podcastsconnect.apple.com/my-podcasts/show/inside-exercise/03a07373-888a-472b-bf7e-a0ff155209b2 YouTube: https://www.youtube.com/@insideexercise Anchor, Google podcasts, Podcast addict etc