How to Fuel Your Marathon: A Guide for Everyday Athletes

At Olway™, we design around the reality of everyday athletes — using science-backed principles to maximize efficiency, minimize gut issues, and keep fueling affordable enough to use every day. This marathon guide outlines how you can put these principles into action as you prepare for your upcoming marathon or long-distance event.

Why fueling matters

From the moment you start running, your body begins drawing on glycogen — its stored carbohydrate. These stores are limited, and while they don’t run out immediately, they steadily decline with every kilometre. By around 90–120 minutes without fuel, glycogen levels are often low enough to cause a sharp drop in performance — what most runners know as “hitting the wall.”

That’s why fueling from the start is essential. Taking in carbohydrates and electrolytes early keeps blood sugar steady, slows glycogen depletion, delays fatigue, and supports decision-making when it matters most (Burke et al., 2011; Jeukendrup, 2011).

Pre-race: The week leading in

In the seven days before your race, focus on meals that steadily top up glycogen stores. Balanced, carbohydrate-rich meals set the stage for performance, while the final 48 hours are about slightly increasing carbs and reducing fibre to ease digestion,

7–3 days out: keep a balanced, carbohydrate-rich diet (rice, pasta, potatoes, bread, fruit, vegetables).

2 days out: slightly increase carbohydrates and reduce fibre to ease digestion.

Morning of: eat a carb-based breakfast 2–3 hours before the start (oatmeal, toast, banana, bagel). Add 30–60g carbs with electrolytes (Performance Drink Mix) at breakfast for an easy boost.

During the race: Why 90g/hr is the sweet spot

Research shows that at 90g/hr, a 2:1 glucose-to-fructose formula oxidizes 86% of carbs consumed. By comparison, a common 1:0.8 formula at 120g/hr oxidizes only 76% (Podlogar et al., 2022). That’s a 10% gap in efficiency — showing that more isn’t always better. At realistic fuelling volumes, 2:1 delivers more usable energy to working muscles, with less risk of stomach issues.

Neutral flavor also matters. After two or three hours, strong flavours can cause “flavour fatigue” and even stomach upset. That’s why our Performance Drink Mix is neutral by design. You can keep it plain or add your own — a splash of juice, squeeze of lemon, or electrolyte tablet.

Aim for 60–90g carbs/hr depending on size, pace, and gut tolerance.
How: Use two Hydration Flasks with Performance Drink Mix with up to 150g carbs + 1,000mg sodium citrate in each. Sip consistently throughout the race.
Learn more on how to use the Hydration Flask to make a gel in 60-seconds linked here.

Post-race: Recovery starts at the finish line

The marathon doesn’t end when you stop running. Recovery nutrition is what sets up your next week of training. Replenishing glycogen and supporting muscle repair quickly will leave you feeling stronger, sooner.

Within 30–60 minutes: aim for 1–1.2g/kg carbohydrate + 20–25g protein. 1–2 servings of Performance Drink Mix provides rapid carbohydrate and electrolyte replenishment — pair it with a protein source for complete recovery. Continue balanced meals through the day to fully restore.

Training well-fuelled

Race-day fuelling strategies should never be a surprise. Practice them in long runs and key workouts. Your body adapts not just to the training load, but to how you fuel. ‘More for less’ is at the core of our design philosophy to enable athletes to train the same way they race.

Final word

“I told myself, stay within myself until 10km to go. If I had the energy, I’d go. For the first time ever, I did. I had more left at the end than I thought possible. I went from 47th to 19th and ran my third-fastest 10km — at the end of a marathon.” – Sub-3 hour Olway™ Athlete

The right fueling plan doesn’t just give you energy — it gives you the confidence to finish strong. At Olway™, we design fueling solutions that are straightforward, science-backed, and accessible, so everyday athletes can perform their best when it matters most.