The Foundation of Ultra Running Fueling: Carbohydrates
Carbohydrates are the cornerstone of any ultra runner's diet, acting as the primary fuel source for sustained, moderate-to-high-intensity efforts. Your body stores carbohydrates as glycogen in the muscles and liver, providing an estimated 2,000 calories of energy. Given that ultra-endurance events can burn up to 18,000 calories, a continuous and strategic intake of carbohydrates is non-negotiable.
Pre-Race Carb Loading
For 36 to 48 hours before an ultra, the goal is to maximize muscle and liver glycogen stores. Experts recommend increasing carbohydrate intake to 10-12 grams per kilogram of body weight per day while moderately reducing protein, fat, and fiber.
- Foods to prioritize: Easily digestible, low-fiber carbohydrate sources like white rice, pasta, oatmeal, and bagels.
- Foods to limit: High-fat, high-fiber, and high-protein foods that can cause gastrointestinal (GI) distress during the race.
Mid-Race Carbohydrate Intake
To sustain performance and prevent 'bonking,' ultra runners should aim to consume 60-90 grams of carbohydrates per hour after the first hour of running. Some elite runners have trained their guts to handle even higher intakes of up to 120 grams per hour.
- Employ multiple transportable carbohydrates: Using a combination of glucose and fructose in a 2:1 ratio can maximize absorption and minimize GI issues, as they use different absorption pathways in the gut.
- Diversify your fuel sources: To combat taste fatigue, alternate between commercial products like gels, chews, and sports drinks, and real food options such as boiled potatoes, rice cakes, and salted pretzels.
The Critical Role of Hydration and Electrolytes
Proper hydration is essential for regulating body temperature, transporting nutrients, and maintaining performance. Equally important is replenishing electrolytes lost through sweat, particularly sodium, to prevent dangerous conditions like hyponatremia.
Your Mid-Race Hydration Strategy
A reliable strategy is to drink to thirst, but during long ultras, a timed approach can be more effective. Aim for 500-750ml of fluid per hour, adjusting for weather and intensity.
- The Power of Sports Drinks: For runs over 90 minutes, sports drinks containing carbohydrates and electrolytes are more effective than plain water at enhancing fluid absorption.
- Listen to your sweat: Individuals who are 'salty sweaters' may need to supplement with electrolyte capsules in addition to sports drinks.
Essential Electrolytes for Ultra Endurance
Electrolytes are electrically charged minerals vital for muscle function and nerve signals.
- Sodium: Crucial for regulating fluid balance. Aim for 500-700mg of sodium per liter of fluid.
- Potassium: Important for muscle contractions and preventing cramps.
- Magnesium and Calcium: Key for muscle contractions, nerve transmission, and energy production.
The Supporting Cast: Protein and Fat
While carbs are king, protein and fat play vital supporting roles, especially in longer events.
During the Ultra
For races exceeding 6 hours, incorporating 5-10 grams of protein per hour can help reduce muscle damage and provide sustained energy. Similarly, small amounts of fat can aid in satiety and provide a long-burning fuel source, particularly during hiking sections.
Post-Race Recovery
After crossing the finish line, prioritize refueling with a 4:1 ratio of carbohydrates to protein within the first 30-60 minutes to maximize glycogen replenishment and muscle repair.
Comparison of Fueling Strategies
| Feature | Gels, Chews & Drinks | Real Food (e.g., potatoes, PB&J) | Fat-Adapted Strategy | High Carb Strategy (80-120g/hr) |
|---|---|---|---|---|
| Convenience | High (Portable, quick intake) | Variable (Can be messy) | High (Lower consumption rate) | Variable (Requires practice) |
| Digestibility | Very High (Engineered for absorption) | Variable (Depends on food choice) | High (Minimal GI distress) | Moderate (Requires gut training) |
| Energy Source | Simple Sugars (Fast release) | Complex and Simple Carbs | Fat (Slow release) | Mostly Simple Sugars |
| Taste Fatigue | High (Can become unpalatable) | Low (Provides variety) | Very Low | High (Needs multiple flavors) |
| Race Length | < 6-8 hours | > 6-8 hours | Very long ultras (50+ miles) | All ultra distances (once adapted) |
Vegetarian and Vegan Ultra Runner Nutrition
A plant-based diet can provide all the necessary nutrients for ultra-endurance with proper planning.
- Protein Sources: Combine plant-based foods to ensure a complete amino acid profile. Excellent options include tofu, tempeh, lentils, beans, and quinoa.
- Key Nutrients: Pay special attention to Vitamin B12 (from fortified foods or supplements), Iron (enhance absorption with Vitamin C), and Calcium.
How to Train Your Gut
Your stomach is a muscle that needs training just like your legs. Regular practice with your race-day nutrition strategy during long training runs is essential for building tolerance. Gradually increase the amount of carbohydrates you consume per hour, starting with easier-to-digest sources before introducing solid foods. Practicing fueling during high-intensity sessions can prepare your gut for race-day stress.
Conclusion
What is the best nutrition for ultra running is not a one-size-fits-all formula, but rather a dynamic, personalized strategy focused on consistent carbohydrate, fluid, and electrolyte intake. The key pillars for success are disciplined training of your gut, smart pre-race preparation, and a commitment to refueling early and often during the event. While commercial products offer convenience, incorporating real foods provides variety and mental relief during long-distance efforts. By adhering to these principles and listening to your body's specific needs, you can optimize your fueling strategy and finish strong. For more in-depth information, consider visiting reliable sports nutrition websites such as Precision Hydration which offers expert advice on hydration and fueling for endurance athletes.
