Marathon running is not just about endurance and mental grit but also about nutrition. Whether recreational or elite, runners invest significant effort, time, and finances in training and racing. To optimise performance and recovery, careful meal planning is essential. The key nutritional goals for marathon runners include:
Fueling training sessions and promoting recovery after workouts.
Maximising training adaptations in key physiological systems.
Attaining optimal body composition while maintaining energy balance.
Meeting daily energy needs
Dietary surveys show that many endurance athletes fail to meet their energy and carbohydrate requirements, often lacking essential vitamins and minerals. This mismatch arises due to several factors:
Suppressed hunger: Intense training can blunt appetite, leading to unintentional energy deficits.
Gastrointestinal discomfort: Prolonged training can redirect blood flow from the digestive system, causing digestive issues.
Desire for a lean physique: Many athletes adopt overly restrictive diets to maintain low body weight for better performance.
Lack of meal planning: Busy training schedules can lead to poor food choices and inadequate energy intake.
Runners should align their food and fluid intake with training loads, consuming more on heavy training days and adjusting accordingly on lighter ones.
Macronutrient needs
Energy requirements
Daily caloric needs depend on factors like basal metabolic rate, training intensity, body composition, and environmental conditions. Running energy costs range between 47-71 kcal/kg of body weight.
Carbohydrates
Carbohydrate intake varies with training levels:
5-7 g/kg/day for moderate exercise (~1 hour/day).
6-10 g/kg/day for more intense sessions (~1-3 hours/day).
8-12 g/kg/day for high-volume training (>4 hours/day).
Competition nutrition: Pre-race carbohydrate loading ranges from 6 g/kg/day (<90 min races) to 10-12 g/kg/day (>90 min races), with a final top-up of 1-4 g/kg in the last 1-4 hours before the event. During the race, fueling recommendations are 30-60 g of carbohydrates per hour for races under 2.5 hours, increasing to up to 90 g/h for longer durations, if tolerated.
Protein: Supporting muscle recovery
Marathoners should consume 1.2-2.0 g/kg/day of protein to prevent muscle breakdown and support recovery. Strength athletes typically require the higher end of this range, while endurance athletes can manage on the lower end. Consuming protein post-exercise helps optimise muscle repair, as muscle protein synthesis remains elevated for 24 hours after training.
Fats: A necessary component
Fat intake should not fall below 20% of total calories. While omega-3s, conjugated linoleic acid (CLA), and medium-chain triglycerides (MCTs) have unclear benefits, limiting fat intake before a race may help prevent gastrointestinal discomfort.
Hydration and micronutrients
Water and electrolytes
Hydration strategies should start with 400-800 ml per hour, adjusted based on sweat rate, climate, and individual needs. Sodium intake should range between 300-600 mg per hour for those with high sweat losses (>1.2 L/h) or prolonged activity (>2 hours).
Nitrates for endurance
Dietary nitrates from sources like beetroot juice (300-600 mg or 3-6 beets) can enhance oxygen efficiency and endurance. Multi-day nitrate loading (6 days before an event) may provide additional benefits.
Antioxidants for recovery
Consuming antioxidant-rich foods like berries, green tea, and dark greens post-exercise can support recovery, though taking them before training may blunt adaptation.
Caffeine for performance boost
A 3-6 mg/kg dose of caffeine taken 30–90 minutes before running can enhance endurance. For sustained performance, “topping up” every 1-2 hours may help, though excessive intake (>9 mg/kg) has diminishing returns and potential side effects.
Probiotics for gut health
Lactobacillus and Bifidobacteria strains may help mitigate gastrointestinal and respiratory symptoms in endurance athletes, ensuring optimal digestion and immune function.
Marathon running is as much about smart fueling as it is about rigorous training. A well-planned nutrition strategy ensures peak performance, optimal recovery, and overall health. Runners should prioritise balanced meals, consistent hydration, and strategic nutrient timing to go the extra mile, literally and figuratively.