Marathon running requires a planned nutritional strategy, often called the “fourth discipline,” alongside physical training. An effective nutrition plan supports the high energy demands of a 26.2-mile race. This plan must be practiced consistently during long training runs to ensure the body tolerates the fuel. Preparation involves strategic eating in the days leading up to the race, the morning of the event, and throughout the run itself. The goal is to maximize the body’s stored energy and maintain stable blood sugar levels to prevent premature fatigue.
The Tapering Week Fuel Strategy
The primary goal of the final week’s nutrition is to achieve glycogen supercompensation, often referred to as “carb-loading.” This process maximizes the storage of carbohydrate energy, or glycogen, in the muscles and liver for use during the race. The most significant increase in carbohydrate intake should occur in the final three to four days before the marathon, coinciding with the reduction in training volume, or taper.
During this period, runners should aim for a high daily carbohydrate intake, typically ranging from 8 to 10 grams of carbohydrate per kilogram of body weight. To make this volume of food manageable and prevent uncomfortable fullness, it is helpful to consume smaller, more frequent meals and snacks.
The type of food consumed is important, focusing on easily digestible, high-glycemic carbohydrates while significantly reducing fiber, fat, and protein intake. Reducing fiber and fat minimizes the risk of gastrointestinal distress on race day, as these macronutrients slow down digestion. Suitable foods include white rice, pasta, white bread, pretzels, and fruit juices, which deliver a dense supply of carbohydrates.
Race Morning Nutrition
The final pre-race meal serves to top off the liver’s glycogen stores, which deplete overnight, and to stabilize blood sugar before the start. This meal must be consumed two to three hours before the race start to allow for proper digestion. Eating too close to the start can lead to digestive issues or a drop in blood sugar once the race begins.
The composition of this meal should be high in simple carbohydrates and low in fiber and fat, which delay gastric emptying. Familiarity is paramount; runners should eat only foods successfully tested during training runs to avoid unexpected stomach problems. Acceptable foods include plain oatmeal, a bagel with jam, toast with a banana, or a sports drink, providing a target of 1 to 4 grams of carbohydrates per kilogram of body weight.
An intentional hydration plan is necessary, aiming for 5 to 10 milliliters of fluid per kilogram of body weight in the two to four hours before the start. This helps prevent dehydration. If the start time is very early, a smaller snack can be consumed closer to the race, especially if the main meal was eaten three or four hours prior.
Fueling During the Marathon
The most immediate fueling challenge during the marathon is preventing the depletion of muscle glycogen, known as “hitting the wall” or “bonking.” Since the body’s stored glycogen typically provides energy for only about 90 minutes of running, consistent replenishment is necessary throughout the event. The general recommendation is to start consuming fuel 30 to 45 minutes into the race and continue at regular intervals.
Runners should target an intake of 30 to 60 grams of carbohydrates per hour after the first hour of running. For faster runners or those with extensive gut training, this intake can be increased to 60 to 90 grams per hour or higher. This hourly carbohydrate goal can be met through various sources, including energy gels, chews, or sports drinks, which contain easily absorbed sugars.
It is essential to consume water or an electrolyte drink with energy gels to facilitate absorption and prevent stomach upset. Hydration and electrolyte balance are equally important. Runners must replace fluids lost through sweat to prevent dehydration and hyponatremia, a condition caused by low sodium concentration. Practicing this hourly fueling and hydration strategy during long training runs ensures the digestive system can handle the constant intake on race day.
Post-Race Recovery Meals
The nutritional focus immediately following the marathon shifts to maximizing the “recovery window.” This is the period when muscle cells are most receptive to restocking energy stores and beginning the repair process. The optimal time to consume a recovery meal is within 30 to 60 minutes of crossing the finish line, which takes advantage of the heightened activity of the enzyme glycogen synthase.
The primary goals are to replenish the severely depleted muscle glycogen and to provide the necessary amino acids for muscle tissue repair. This is best achieved by consuming a combination of carbohydrates and protein, with the recommended ratio being approximately 4:1 carbohydrates to protein. This specific ratio has been shown to boost glycogen resynthesis rates more effectively than carbohydrates alone.
For most runners, this translates to an intake of about 60 to 90 grams of carbohydrates and 20 to 30 grams of protein in the immediate post-race period. Practical examples of foods that fit this profile include chocolate milk, a recovery shake, or a turkey sandwich on white bread. Fluid and electrolyte replacement must also be a high priority to restore the body’s fluid balance, focusing on consuming 16 to 24 ounces of fluid every 60 to 90 minutes for the first few hours.