Marathon Fueling Strategy 2026: Carbs, Hydration, and Electrolytes Explained

Fueling a marathon isn’t guesswork—it’s a plan. To run your best, you’ll match carbohydrate intake, hydration, and electrolytes to your pace, finish time, and weather. At marathon intensity, muscle and liver glycogen—the body’s carbohydrate store—can support roughly 90–120 minutes before declining, which is why in-race fueling is mandatory to avoid “hitting the wall” and to sustain steady pacing and decision-making late in the race (basic marathon nutrition) Korey Stringer Institute’s guide for first-time marathoners. This Hiking Manual guide gives you clear, numeric targets (grams of carbs per hour, ml of fluid per hour, mg of sodium per hour), practical schedules, and logistics that work on race day—and in training long runs—so your energy is predictably strong from start to finish.