This teaching provides a comprehensive overview of the physiological, nutritional, and biochemical principles that support athletic performance, recovery, and adaptation. It begins with the fundamentals of energy metabolism, examining how the ATP-PCr system, anaerobic glycolysis, and aerobic pathways contribute to different sport demands. The course explores how hydration regulates thermoregulation, cardiovascular function, osmotic balance, and muscular efficiency, emphasizing practical strategies before, during, and after exercise to prevent dehydration and optimize performance. A major focus is placed on macronutrient and micronutrient needs, and key ergogenic supplements, such as β-alanine for buffering capacity, HMB for reducing muscle breakdown, glutamine for immune and gut support, creatine for power output, and amino acid strategies using whey, casein, BCAAs, and EAAs. Finally, practical applications across sports connect theoretical knowledge with sport-specific energy demands and recovery needs.