Fuel Up to Smash Your Endurance Goals:

Carb-Load Like a Pro!

Whether you’re lining up for a marathon, ultra-endurance event, or all-day sufferfest, proper pre-race nutrition can be the difference between bonking at the wall and unlocking next-level performance.

While pretty much all endurance athletes understand the importance of staying fuelled during an event, I find that the actual understanding how to do this can be pretty lacking.

It can feel like a mindfield… so I’m going to break it down and make it as simple as I can for you.

In a nutshell it means optimising what you eat in the days beforehand and it is a massively underrated part of the high-performance equation.

By strategically carb-loading and topping off fuel stores through precise nutrient timing and food choices, you can start your biggest races topped up with maximum muscle glycogen levels – allowing you to go harder, longer, and put your training to its fullest test.

Carbohydrate loading to maximize glycogen stores

Glycogen stores can deplete relatively quickly during prolonged endurance events, which is why carbohydrate loading in the days leading up to the event is so important.

Here are the headlines:

  • Muscles store glycogen as the primary fuel source for high-intensity exercise lasting longer than 90-120 minutes.
  • A well-trained endurance athlete may have 350-700g of glycogen stored in their muscles prior to carb loading.
  • During a marathon or long endurance event, these glycogen stores can become depleted after about 2-3 hours of activity.
  • Glycogen depletion is a major cause of hitting “the wall” or bonking during prolonged exercise when the muscles run out of easily accessible carbohydrate fuel.
  • The carb loading protocol aims to maximize muscle and liver glycogen levels by tapering training and consuming a high-carb diet (7-12g/kg bodyweight) in the 1-3 days before the event.
  • Proper carb loading can increase the total glycogen stores by 50-90% over normal levels, delaying fatigue.
  • The timing of carb loading is important – loading too early results in glycogen depletion before the event.

Good Pre Race Foods to Include in your Carb Load Phase:

  • White rice or pasta with a simple tomato/marinara sauce
  • White or sweet potatoes
  • Bagels or English muffins with jam/honey
  • Bananas
  • Rice cakes or crisp breads
  • Sports drinks and electrolyte beverages
  • Low-fiber cereals such as porridge, Ready Brek or Shredded Wheat.

Simple Pre-Race Meal Examples:

  • Baked potato with salt, small side salad, and a sports beverage
  • Plate of pasta with marinara sauce and a banana
  • Bagel with peanut butter, a handful of pretzels, and a smoothie
  • White rice, grilled chicken, steamed veggies, and an electrolyte drink
  • Oatmeal with honey, a piece of toast with jam, and a fruit cup

The key things that make these “simple” are:

  • Easily digestible carb sources like rice, potatoes, pasta
  • Limited fiber, fat and protein to avoid GI distress
  • Hydrating fluids like sports drinks
  • Familiar, bland foods that the athlete tolerates well
  • Single-plate or bowl meals for easy consumption

The focus is on providing high-quality carbs to top off glycogen stores, along with some protein, antioxidants, and fluids – without overwhelming the system before the endurance event begins.

Other things to consider:

Optimal Timing and Composition of the Pre-Event Meal:

  • Timing is crucial – the pre-event meal should be consumed 3-4 hours before the start to allow for proper digestion and absorption
  • Composition should be high in easily digestible carbs (e.g. white rice, pasta, potatoes, bread) and low in fat/fiber to minimize GI distress
  • Fluids should be included to top off hydration levels
  • Some protein can be included, but the focus should be on carb-rich foods
  • Individualize based on personal tolerances – avoid any foods that typically cause GI issues
  • Portion sizes depend on the event duration but usually around 3-4g/kg carbs

Hydration Strategies Before the Event:

  • Begin hydrating heavily 2-3 days out by increasing fluid intake
  • Aim to consume 5-10mL per kg bodyweight about 2-4 hours pre-race
  • Include sodium in pre-race hydration to better retain fluids
  • Monitor urine color to ensure proper hydration levels
  • Don’t over-hydrate excessively, as this can cause hyponatremia
  • Customize hydration based on individual sweat rates and event conditions


The key for pre-event fueling is to maximize carb/fuel stores through proper loading, time the final fuel intake for optimal digestion and utilization, and ensure adequate but not excessive hydration levels heading into the endurance event.

This primes the body’s energy systems for the upcoming demands. It ensures you have done everything you can via your nutrition to back up the hard work you have put in via your training.

  • RED-S; Relative Energy Deficiency in Sport
  • Periodisation Deep Dive
  • Low Energy Availability (LEA):
  • How do we burn calories? Let me count the ways…
  • Fuel Up to Smash Your Endurance Goals:
  • Supercompensation – the effective but counterintuitive training methodology.
  • Practical Mental Coping Strategies for Endurance Lows
  • Avoiding the Euphoria-Despair Roller Coaster in Endurance Racing
  • The Importance of Periodisation in Endurance Training
  • Monitoring and Managing Fatigue in Endurance Training
  • All About Stress
  • Train your breathing for better race results
  • Does how you breathe really matter?
  • Unlocking Your Athletic Potential: Nature vs. Nurture
  • Recovery: The Unsung Hero of Triumphs
  • Build Consistently, Adapt Relentlessly
  • Minimum effort. Maximum Impact
  • Specificity is KING for Endurance
  • Strength Reigns Supreme in Endurance
  • The 5 Pillars of the DB Training Methodology
  • The Three Biggest Mistakes Endurance Athletes makeā€¦
  • Mastering the SAID Principle for Endurance Training Success
  • Mastering Heart Rate Zones for Peak Endurance Performance
  • Setting your HR Zones & How to Judge Progress
  • How to Test your Lactate Threshold
  • Why Lactate Threshold trumps Max Heart Rate for Endurance Training
  • Golden Rule #5 Extreme Ownership
  • Golden Rule #4 100% Effort
  • Golden Rule #3 Focus on You
  • Race Day Nutrition – A Rough Guide