Fuelling is one of the most important—and often overlooked—aspects of full distance triathlon performance. Covering 140.6 miles across swim, bike, and run places extraordinary demands on energy availability, hydration, and electrolyte balance. Without a precise fuelling strategy, athletes risk bonking, dehydration, or muscle cramps that can derail months of preparation. By planning nutrition carefully—before, during, and after the race—athletes can maintain steady energy, delay fatigue, and give themselves the best chance to perform consistently across all three disciplines and finish strong down the chute.