Marathon Fueling Guide for Runners

Running a marathon is a mental and physical challenge requiring dedication, training, and strategy. The best training must be paired with a healthy nutrition and hydration plan. Proper fueling can make the difference between hitting a new personal best and hitting the wall.

Here are some tips on fueling up before, during, and after the race.

1️⃣ Pre-Race Nutrition
Carb Loading: Boosting Muscle Glycogen
One of the most critical components of marathon preparation is “carb loading.” Carbohydrates are stored in your muscles and liver as glycogen, providing essential energy for endurance exercise. In the 2-3 days leading up to the marathon, runners can optimize their glycogen stores by increasing their intake of complex carbs, including foods like rice and gluten-free bread. Carb loading helps ensure your muscles have the energy they need for the long-distance challenge.
How to Carb Load:
Aim for about 3.5-5.5 grams of carbohydrates per pound of body weight each day.
Spread your intake evenly throughout the day to prevent digestive issues.
Stick with familiar foods to avoid stomach upset.
The Night-Before Snack
In addition to carb loading, a small snack the night before can help keep blood sugar levels stable overnight. Opt for easy-to-digest carbs, such as blueberries or gluten-free toast. This simple snack should keep you fueled without feeling overly full.

2️⃣ Supplements for Stamina
Supplements can be helpful to support endurance, muscle function, and bone strength in the weeks leading up to your marathon.

Let’s review some essential supplements and how they can benefit you:
BCAAs (Branched-Chain Amino Acids)
BCAAs are popular among endurance athletes because they help reduce muscle breakdown during prolonged exercise. Taking BCAAs about 30 minutes before the marathon may help you maintain muscle function, reduce soreness, and delay fatigue. Studies suggest BCAAs can assist with preserving glycogen stores, which is crucial for maintaining energy on race day.
Suggested Dosage: Around 5-10 grams taken shortly before exercise.
Magnesium: Muscle Health and Cramps
Magnesium plays a crucial role in muscle function and nerve conduction. It helps prevent cramps and muscle spasms, which are common issues during intense exercise. A marathon places enormous stress on the muscles, and magnesium supports muscle contraction and relaxation, reducing your risk of cramping.
Suggested Dosage: 200 mg daily for about a week leading up to the marathon.
Calcium & Vitamin D for Bone Strength
Running places a high-impact load on your bones, so keeping them strong and resilient is essential. Calcium supports bone strength, while Vitamin D helps your body absorb calcium more efficiently. Ensuring adequate intake can help prevent injuries like stress fractures and shin splints that could derail your training or impact your race day performance.
Suggested Dosage: 1000-1200 mg of calcium daily and at least 1000 IU of Vitamin D. Taking these with food will aid absorption.

3️⃣ Race Day Fuel
Fueling on the day of the marathon requires balance. Eating too much or too close to the start of the race can lead to digestive discomfort, while insufficient fuel can leave you struggling to keep up the pace.

Here are the essentials:
Pre-Race Meal
Your pre-race meal sets the stage for a strong performance. Choose easily digestible carbs like oatmeal, gluten-free toast, or an energy bar, ideally eaten 2-3 hours before race time, as this helps your body process and store energy while keeping your stomach light enough to avoid cramping. Avoid high-fat, high-fiber foods that may slow digestion or cause GI distress.
Pre-Race Meal Example:
Slices of gluten-free toast with a thin spread of organic strawberry jelly
An energy bar with simple ingredients
A bowl of organic oatmeal with blueberries
Hydration & Electrolytes
Hydration is crucial but requires more than just water. Electrolytes, including sodium, potassium, and magnesium, are essential to balance your hydration levels, prevent cramps, and regulate muscle contractions. Begin your hydration regimen when you wake up by sipping electrolyte water. Avoid overhydrating, as that can lead to hyponatremia, a dangerous dilution of sodium levels.
Energy Gels During the Race
You’ll get a quick energy boost to maintain performance as you burn through your glycogen stores. Energy gels are designed for fast absorption, providing essential carbs without the bulk. Take one gel every 30 to 45 minutes during the marathon to stabilize glycogen levels. During training, try different brands and flavors to find what sits well with your stomach.
Pro Tips for Gel Intake:
Chase each gel with water to prevent digestive discomfort.
Experiment with timing and flavor options in training runs to ensure comfort.

4️⃣ Rehydrate & Replenish Post-Race
After you finish, it’s time to focus on recovery. The sooner you start replenishing your body, the quicker you recover.

Here’s some of what to consume post-race:
Protein & Carbs: Muscle Replenishment
The ideal post-race snack contains protein and carbohydrates to aid muscle recovery and replenish glycogen stores. Within 30 minutes of finishing, try a smoothie or a protein shake that combines both macronutrients. Look for a ratio of about 3:1 carbs to protein for optimal recovery.
Sample Recovery Shake:
One cup of organic blueberries
1 cup almond milk
One scoop of protein powder
A handful of spinach (optional)
Electrolyte Refill
During the race, you lose electrolytes through sweat, so it’s super important to replenish them after you finish. Look for electrolyte-rich drinks containing sodium, potassium, and magnesium or natural alternatives like coconut water. Maintaining electrolyte balance post-race will help prevent headaches, fatigue, and muscle cramping.

Final Tips for Success
Preparing for a marathon involves fine-tuning your training and nutrition plan to give you the best chance of success. Here are a few final tips:
Test Your Nutrition Strategy in Training: Each runner reacts differently, so test your carb-loading, race-day meals, and supplements during training to see what works best.
Practice Timing: Timing your nutrition and hydration is just as important as the foods you consume. Take note of what times work for pre-race meals, gels during your run, and recovery snacks.
Stay Hydrated in the Days Leading Up: Hydration starts days before the marathon, so keep drinking water leading up to the event, but avoid excessive water intake on race day to prevent over-hydration.
Listen to Your Body: Every runner has different needs, so pay attention to what your body tells you during training. Trust your instincts and adjust your plan as necessary.

Conclusion
Fueling effectively for a marathon involves thoughtful planning and understanding your body before, during, and after the race. From carb loading to BCAAs and electrolyte gels to post-race protein shakes, every step in your fueling journey is crucial in achieving peak performance. Remember, the best marathon experience is feeling strong, energized, and ready to conquer each mile. So prepare well, experiment in training, and stay focused and fueled on race day to reach that finish line.

You’ve got this!

Tags: fueling guide for runners, marathon, mental health, Nancy Guberti, nutrition for runners, running guide, total wellness