How many calories should you eat the week before a marathon?

According to sports nutritionists, endurance athletes can require up to 7,000 calories per day during intense training phases, but this shifts dramatically during race week. Determining how many calories should you eat the week before a marathon is crucial for topping off glycogen stores without feeling bloated or sluggish on race day.

Quick Summary

Guidance on adjusting calorie intake during the tapering phase before a marathon. The focus shifts to increasing carbohydrate proportion while decreasing fat and protein, ensuring maximal glycogen storage for race day. Hydration and avoiding high-fiber foods are also key to a successful fueling strategy.

Key Points

• Shift Calorie Composition: The week before a marathon, increase the percentage of calories from carbohydrates while reducing fat and protein, rather than just increasing total calories.

• Prioritize Simple Carbs: In the final 2-3 days, switch to easily digestible, low-fiber carbs like white pasta and bagels to maximize glycogen storage and prevent GI distress.

• Maximize Glycogen Storage: The primary goal is to fully stock your muscles with glycogen, which serves as the main energy source during the race.

• Stay Hydrated: Consistent hydration is crucial throughout the taper week, as glycogen stores require water.

• Avoid Experimentation: Stick to familiar foods and fueling strategies you have practiced during training runs to avoid race-day surprises.

• Don't Overeat: Eating too much can cause bloating and lethargy. The focus is on a strategic macronutrient shift, not simply consuming excessive amounts of food.

The final week before a marathon, known as taper week, is a critical time for nutrition. The focus shifts to maximizing muscle glycogen stores, the primary fuel source for the race, as training volume decreases. This involves strategic carb-loading, which is more about adjusting macronutrient ratios than simply overeating. To avoid unnecessary weight gain, the goal is to increase the percentage of calories from carbohydrates, not necessarily the total calorie count.

Days 7-5: Transitioning Your Diet

In the initial days of race week, gradually increase the proportion of carbohydrates while slightly reducing protein and fat. Choose carb-dense foods like oatmeal, sweet potatoes, or brown rice. Stay well-hydrated, and start reducing high-fiber foods to prevent potential GI issues on race day.

Days 4-2: Intensifying Carb-Loading

During peak carb-loading, aim for 8-10 grams of carbohydrates per kilogram of body weight daily. Focus on easily digestible, low-fiber carbs such as white pasta, white rice, and plain bagels. Eating smaller, more frequent meals can help reach the carbohydrate goal without feeling overly full. Reducing fat and protein facilitates carbohydrate consumption and digestion.

Day 1: Final Fueling and Hydration

The day before the marathon, have a modest, high-carbohydrate dinner that is low in fat, fiber, and protein. Eat early and stick to familiar foods. Continue to prioritize hydration, aiming for clear or pale yellow urine.

Comparative Meal Strategies: Training vs. Taper Week

Nutrient Goal	Training (Hard Day)	Taper Week (Days 2-4)
Calorie Source	Balanced macros (high carbs, moderate protein/fat)	Primarily carbohydrates (85-95%)
Carbohydrate Focus	Complex carbs (brown rice, whole wheat pasta)	Simple, low-fiber carbs (white rice, white pasta)
Protein Intake	High (1.8-2.0 g/kg) for repair	Moderate to lower (to make room for carbs)
Fat Intake	Moderate for overall energy	Lower (reduce digestion time)
Fiber Content	Moderate to high for general health	Low to minimize GI issues before race
Meal Timing	Spread throughout the day, emphasizing post-run recovery	Small, frequent carb-rich meals to maximize glycogen storage

Conclusion

A strategic nutritional shift in the final week, focusing on carbohydrates, is key to marathon fueling. Adjusting macronutrients, prioritizing easy-to-digest carbs, and ensuring hydration helps maximize glycogen stores and prepares the body for peak performance. For more on sports nutrition, refer to resources like the {Link: International Society of Sports Nutrition https://jissn.biomedcentral.com/}.

Frequently Asked Questions

Should I eat more overall calories the week before a marathon?

No, you don't necessarily need to increase your total calorie count. The key is to increase the proportion of carbohydrates in your diet while decreasing fat and protein, especially in the final 2-4 days, to maximize glycogen stores.

What is carb-loading, and how does it work?

Carb-loading is a strategy where endurance athletes increase their carbohydrate intake in the 2-3 days before a race to maximize the amount of glycogen stored in their muscles. Glycogen is the body's main energy source during a marathon, and full stores help prevent 'hitting the wall'.

What specific foods should I eat during carb-loading?

Focus on easily digestible, low-fiber carbohydrate sources. Good examples include white pasta, white rice, bagels, potatoes, oatmeal, and sports drinks. Minimizing fiber helps prevent gastrointestinal issues.

What foods should I avoid the week before the race?

Avoid high-fiber foods, fatty and greasy foods, spicy foods, and alcohol, especially in the 48 hours leading up to the race. These can cause digestive upset and discomfort.

Will I gain weight during taper week, and is that normal?

Yes, it is common to gain 1-2 kilograms of water weight during carb-loading. This is normal and beneficial, as every gram of stored carbohydrate retains several grams of water, which helps with hydration and performance.

How should my final pre-race dinner look?

Your dinner the night before should be high in carbohydrates, moderate in protein, and low in fat and fiber. Eat it early to allow for digestion. A simple pasta with marinara and lean chicken is a good choice.

How important is hydration during race week?

Hydration is extremely important. As you carb-load, your body needs water to store glycogen. Staying well-hydrated throughout the week ensures your muscles are primed for race day.