Rethinking Your Marathon Week Plate
Many runners fall into the trap of thinking they can eat whatever they want during marathon week, viewing it as a reward for months of hard training. However, this common misconception can leave you feeling heavy and sluggish on race day. The real goal is not to eat more overall calories, but to strategically adjust your macronutrient intake to maximize your body's glycogen stores, which act as the primary fuel source for endurance events.
The Science Behind Carb Loading
Carbohydrate loading is the practice of increasing your carbohydrate intake in the days leading up to a long race to fully stock your muscles and liver with glycogen. As you enter the tapering phase of training, your mileage and exercise intensity decrease significantly, but your body continues to use energy for recovery and to repair muscle damage. By increasing the percentage of carbohydrates in your diet during this period, you create a surplus that is stored as glycogen, rather than using it to fuel daily runs.
Research indicates that as few as two to three days of increased carbohydrate consumption, combined with rest, is enough to optimize these stores. For every gram of glycogen stored, your body also stores several grams of water, which helps with hydration during the race. This may lead to a moderate weight gain of 1 to 3 pounds, which is normal and beneficial.
Carb Loading vs. Overeating
The key distinction is between strategic carbohydrate manipulation and simple overeating. Your total calorie intake may not need to increase, and in some cases, might even decrease slightly due to the reduced training load. Instead, you should decrease the intake of fats and proteins to make room for the higher carbohydrate percentage. This prevents you from feeling bloated and lethargic from an excess of calories. The outdated method of intentionally depleting carbohydrate stores before loading is no longer recommended.
What to Eat and What to Avoid
During race week, prioritize nutrient-dense, high-carbohydrate foods that are easy to digest. Stick to foods you've tested during training to avoid any last-minute gastrointestinal (GI) distress. A good rule of thumb is to start slightly increasing carb intake five days out, and focus on clean, low-fiber options in the final 48 hours.
Foods to Favor:
- Complex Carbohydrates: Oats, potatoes, rice, pasta, quinoa, and whole-grain bread (in the early part of the week).
- Simple Sugars: Sports drinks, bananas, and energy gels are good for topping off stores closer to race time and can be used to spread intake throughout the day.
- Lean Protein: Fish, poultry, and eggs in moderate portions.
- Healthy Fats: Olive oil, avocado, and nuts in moderate amounts early in the week.
- Fruits and Vegetables: Focus on lower-fiber options like cooked vegetables and peeled fruit in the last few days.
Foods to Avoid (Especially in the final 48 hours):
- High-Fiber Foods: Raw vegetables, bran, lentils, and pulses can cause cramping and unwanted bathroom breaks.
- High-Fat Foods: Fried foods, creamy sauces, and fatty meats digest slowly and can feel heavy.
- Spicy Foods: Can irritate the GI tract.
- Alcohol: Contributes to dehydration and can negatively impact sleep.
- New or Unfamiliar Foods: Race week is not the time to experiment.
A Tale of Two Diets: Training vs. Race Week
| Normal Heavy Training Week | Race Week (Final 3 Days) | |
|---|---|---|
| Training Volume | High Intensity & Volume | Tapered, Very Low |
| Carbohydrate Percentage | 55-65% | Up to 70% |
| Protein Percentage | Moderate (15-20%) | Reduced to make room for carbs |
| Fat Percentage | Moderate (20-30%) | Minimized |
| Total Calories | Higher to support training | Roughly consistent with taper |
| Fiber Intake | Normal, high-fiber encouraged | Reduced to avoid GI issues |
| Key Focus | Fueling workouts & recovery | Topping off glycogen stores for race day |
The Final 48 Hours and Race Morning
The 48 hours leading up to the race are crucial. Many experts recommend having your last major, carb-heavy meal two nights before, not the night immediately preceding the race. This allows for complete digestion and avoids waking up feeling full and bloated. For your meal the night before, opt for a simple, smaller portion of a tried-and-true carb source like plain pasta or white rice.
On race morning, eat a familiar, easily digestible, and carbohydrate-rich breakfast 2-3 hours before the start. Options include oatmeal with a banana or toast with nut butter. A small snack or gel 30-40 minutes before the gun goes off can provide a final top-up of energy. Staying well-hydrated throughout the entire week, and especially on race morning, is also critical.
Conclusion
So, should you eat more the week of a marathon? The simple answer is no, not necessarily in terms of total calories. The key is smarter, not necessarily more, eating. Your focus should be on a purposeful shift in your diet's composition, boosting your carbohydrate percentage to fill your body's energy reserves while reducing your training volume. By following a strategic carb-loading plan and avoiding last-minute changes, you can ensure your body is perfectly primed for a strong and successful race day. Proper fueling during this final week is the last, and often most important, part of your marathon preparation.
