In this episode, we discuss the concept of "fuelling for the work required," the importance of carbohydrate availability in sports training and how to optimize the training stimulus by managing glycogen content with our guest, Dr. Sam Impey. We explore the flexibility of the human body in fuel storage and utilization, especially in endurance training and glycogen depletion. We discuss different methods of achieving a train low environment, such as exercising in the morning after an overnight fast, training twice in one day and the "sleep low" model. These approaches can lead to meaningful changes in physiology and potentially help athletes improve their performance by adapting to various energy states. We also delve into the complexities of the "sleep low" strategy and its impact on energy stress during exercise, as well as the potential benefits and drawbacks of incorporating low-carbohydrate sessions into an athlete's training regimen. Additionally, we explore the challenges faced by high-volume athletes in maintaining energy availability and achieving optimal health outcomes. Plus we explore the concept of a 3-500 calorie deficit per day for endurance athletes looking to improve their body composition without compromising their performance. LINKS: Dr Sam Impey on Twitter at https://twitter.com/SamImpey_ Hexis at https://www.hexis.live/