This podcast episode discusses various topics related to exercise physiology, metabolic function, and their impact on health and performance. The episode covers the decision to rely on listener support instead of advertising for funding, the physiological demands of professional cycling, the concept of energy systems and zones, the role of lactate as both a signaling molecule and a fuel source, the importance of mitochondrial function, the relationship between fitness and glycogen storage capacity, the correlation between heart rate and lactate levels, the challenges of carbohydrate restriction for elite athletes, the metabolic profile of Tour de France cyclists, and the potential impact of metformin on lactate levels and exercise benefits. The episode also explores the relationship between exercise, insulin, and glucose uptake, the importance of Zone 2 training for health improvement, the role of mitochondria in weight loss and cancer, the role of lactate as a signaling molecule in cancer, the impact of performance-enhancing drugs on cycling, and the unique characteristics of legendary cyclist Miguel Indurain.