In this episode of Fast Physiology on the Critical Oxygen Podcast, Dave Schell and I discuss fatigue. We explore the physiological mechanisms, the role of ATP in muscle contraction, and how specific training can enhance fatigue resistance. We discuss the protective nature of fatigue (i.e. why we fatigue), the importance of understanding metabolic acidosis, and the need for tailored training to prepare for endurance events. The conversation emphasizes the multifactorial aspects of fatigue and the significance of maintaining ATP levels during exercise.