The Melbourne Ironman 70.3 is one of the most physically demanding single-day events an athlete can take on — and nutrition is arguably the most important factor outside of your training. If you want to avoid hitting the wall, bonking, cramping, or GI distress, a race-specific fuelling plan is essential.
Here’s your complete, phase-by-phase Ironman 70.3 nutrition strategy tailored for Melbourne.
What Is an Ironman 70.3?
An Ironman 70.3 — also called a Half Ironman — consists of:
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1.9 km swim
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90 km bike ride
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21.1 km run
That’s 113 km (70.3 miles) of endurance racing. The average finish time ranges from 4–7 hours depending on conditions and experience. To fuel this, your body needs energy, electrolytes, fluid, and a rock-solid strategy.
The Key Components of Ironman 70.3 Nutrition
Ironman racing pushes the limits of your metabolic and muscular systems. Nutrition should focus on:
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Carbohydrates – primary energy source; aim for 60–120g/hr
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Electrolytes (sodium, magnesium, potassium) – prevent cramps and support hydration
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Fluids – replace sweat losses without overhydrating
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Gastrointestinal tolerance – avoid GI distress by using tested, natural fuel
One Week Before: Increase Carbohydrate Intake
In the week leading up to race day, begin increasing your carbohydrate intake to 7–10g per kg of body weight daily, especially from Wednesday onward.
Focus on:
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White rice, pasta, bread, bananas, and juice
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Organic Performance Carbohydrates to easily boost carb intake without bloating
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Add Electrolytes to your water daily to support hydration status
Training volume will taper, so this will help build full glycogen stores and maintain energy levels.
Day Before the Race: Top Off Glycogen & Hydration
The 24 hours before your race should focus on:
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Eating familiar, easy-to-digest, high-carb, low-fibre meals
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Drinking fluids consistently throughout the day
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Adding Organic Performance Carbohydrates + Electrolytes to your fluids to maintain glycogen and sodium levels
Example meals:
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Breakfast: Toast with jam, banana, and electrolyte drink
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Lunch: White rice with lean chicken, electrolyte water
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Dinner: Pasta with tomato sauce, light protein, and carb drink
Avoid anything heavy, greasy, or high in fibre that could upset your stomach on race day.
Race Morning Nutrition Plan
Eat 2.5–3 hours before the start to allow time for digestion.
Race day meal options:
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White toast with jam + banana
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Low-fibre oats with maple syrup
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Rice pudding with honey
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Electrolytes in water + small coffee if tolerated
~80–120g of carbohydrates is ideal. Continue sipping water or electrolyte drink up to 30 minutes before the swim.
Race Nutrition Plan
The Swim (1.9 km)
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You can’t eat during the swim, but we recommend sipping a Re-Fuel Gel Flask with 20–30g carbs + electrolytes 15–20 minutes before the swim start.
The Bike (90 km / ~2.5–3.5 hours)
The bike leg is your best opportunity to take in large amounts of fuel.
Nutrition goals on the bike:
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240–360g carbs total (aim for 90–120g/hr)
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Electrolytes + extra sodium if you're a heavy or salty sweater
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At least 500–750ml fluid per hour
Recommended setup:
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2 bottles with 120–180g carbs each from Organic Performance Carbohydrates + Electrolytes
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1 third bottle with plain water, which can be refilled at aid stations
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Optional solid food: 1–2 oat bars or rice cakes (early in the bike to line the stomach and slow digestion)
This setup minimises GI distress and keeps energy steady heading into the run.
The Run (21.1 km / ~1.5–2.5 hours)
The run is where many athletes hit the wall — but not you.
Run fueling plan:
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2 x Re-Fuel Gel Flasks, each containing 80–90g Carbohydrates + Electrolytes + sodium
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Sip small amounts every 15–20 minutes
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Drink water at every aid station to help absorption
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Optional: Grab fruit (banana, watermelon) if hunger kicks in or your stomach needs a break from gels
Target 60–90g carbs/hr on the run. Stick to a strategy you’ve practiced in training.
Post-Race Recovery Nutrition
The first 30–60 minutes post-race are key:
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25–30g protein to start muscle repair
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60g carbohydrates to replenish glycogen
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Continue drinking water + electrolytes
Best options:
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Organic Performance Plant Protein shake + banana
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Smoothie with oats, fruit, protein
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Rehydration with electrolyte drink
Then eat a proper recovery meal (carbs + protein) within 2 hours.
Final Thoughts
Your Ironman 70.3 nutrition strategy is your secret weapon. By fuelling with real, natural ingredients, hitting your carb targets, and practising your plan before race day, you’ll give yourself the best chance to feel strong from the first stroke to the final step.
Train hard. Fuel smarter. Race strong.
Explore the full Organic Performance endurance range including: