Dr José González-Alonso, expert in exercise in the heat and dehydration, discusses muscle blood flow, fluid ingestion during exercise, cardiovascular drift, dehydration's effect on performance, and the impact of fluid intake on muscle glycogen use. They also touch on topics like blood osmolality, heat and humidity's effects on exercise, and the unknowns in the field. The podcast delves into the relationship between fluid intake, urine production, and osmolality. Additionally, it explores the complexity of fatigue and the role of the periphery in the cardiovascular system.