Marathon Nutrition & Supplement Guide

Proper marathon training doesn’t stop at your running shoes. If you want to perform at your best on race day, your nutrition leading up to the marathon is just as important as your mileage. What you eat in the final days before your event can dramatically influence your energy, endurance, recovery, and mindset.

This guide breaks down exactly what to eat before a marathon, including a full race week meal plan, top supplements, and crucial foods to avoid.

Why Nutrition Matters in the Week Before a Marathon

The final 5–7 days before a race are when you prepare your body’s energy stores for the big effort. The focus is on:

  • Maximising glycogen stores through smart carb-loading

  • Staying hydrated with electrolytes

  • Supporting recovery and energy with effective supplements

  • Avoiding gut discomfort by cutting trigger foods

How to Fuel the Week Before a Marathon

5–7 Days Out: Balanced, Nutrient-Dense Meals

Start by eating well-rounded meals that include:

  • Complex carbohydrates: brown rice, oats, sweet potatoes

  • Lean proteins: chicken, fish, tofu

  • Healthy fats: olive oil, avocado, nut butters

  • Hydration: Increase water intake and start adding electrolytes

Sample Day:

  • Breakfast: Oats with banana, honey & almond butter

  • Lunch: Grilled chicken, quinoa, roasted vegetables & hummus

  • Dinner: Salmon, brown rice & steamed greens

  • Snacks: Greek yoghurt, energy bars, electrolyte drinks

2–3 Days Out: Time to Start Carb-Loading

Carb-loading boosts muscle glycogen stores, which delay fatigue and power you through the later miles of the race.

Shift your meals toward higher-carb, lower-fat, lower-fibre options. Think easy-to-digest and familiar.

Sample Meals:

  • Breakfast: Whole grain toast with jam & low-fat milk

  • Lunch: Pasta with tomato sauce & lean turkey

  • Dinner: White rice with grilled chicken or tofu

  • Snacks: Bananas, rice cakes, Puresport Electrolytes

What to Eat the Day Before and Morning of Your Marathon

Night Before the Race

Stick to simple, familiar foods that won’t upset your stomach.

  • Go-to meal: White pasta with olive oil or tomato-based sauce and grilled protein

  • Avoid: Heavy sauces, high-fibre veg, spicy foods, or anything new

  • Tip: Eat earlier in the evening so you’re not going to bed full

Morning of the Race

Aim to eat 2–3 hours before the start with a light, carb-rich breakfast.

Pre-Race Breakfast Ideas:

  • Bagel with peanut butter and banana

  • Porridge with honey and berries

  • Rice cakes with jam and a protein shake

Hydrate well, but don’t overdo it—sip on water or an electrolyte mix up to the start line.

Best Supplements to Take Before a Marathon

Smart supplementation can help top off your preparation and keep you sharp on race day.

Top Puresport Supplements for Marathon Runners:

  • Electrolytes – Stay hydrated and prevent cramping

  • Creatine Monohydrate – Supports muscle endurance and recovery, ideal during taper week

  • Sleep Supplements – Calm nerves and support restful sleep the night before

Foods to Avoid Before a Marathon

Some foods are notorious for causing mid-race problems. Skip anything that could disrupt your gut, sleep, or hydration status.

Avoid These Foods:

  • High-fibre vegetables (broccoli, beans, cauliflower)

  • Heavy, greasy meals

  • Spicy or rich dishes

  • Alcohol

  • New or unfamiliar foods

  • Too much caffeine

Final Thoughts: Race Day Starts in the Kitchen

Fueling your body correctly in the week leading up to a marathon can make all the difference. From carb-loading to hydration and supplement support, every decision impacts your endurance, recovery, and mental focus.

By following this marathon nutrition guide and avoiding the common mistakes, you’ll arrive at the start line strong, confident, and ready to run your best race yet.

Previous
Previous

Summer Running & Hydration

Next
Next

Vitamin D3 + K2 Benefits