Perth gives you a flat, fast course with one honest complication: wind. Running into a headwind at goal pace costs more energy than the same pace in still air, and that extra cost is paid in carbohydrate, not willpower.
Plan for the higher end of your carbohydrate range if the forecast is breezy, and take fuel on the sheltered sections rather than fighting a headwind and a bottle at the same time.
What the race demands
Course
Flat, exposed river and coastal sections
Season
Cool winter mornings, often breezy
Main risk
Headwind sections raising energy cost above planned pace
Second risk
Cool start masking real fluid and sodium losses
Carbohydrate and sodium targets
- Sub-3:00: 70 to 90g of carbohydrate per hour from a dual-carb source
- 3:00 to 4:00: 50 to 75g of carbohydrate per hour
- 4:00 to 5:00: 40 to 60g of carbohydrate per hour
- Sodium: 300 to 800mg per hour depending on your measured sweat rate
HYDRAX CORE delivers 85g of dual-carb fuel and 980mg of sodium per serve, so hitting the numbers above is arithmetic rather than guesswork. HYDRAX PRIMER covers the pre-race window with 29g of carbohydrate and 1,313mg of sodium. Run the free fuelling strategy tool to convert these ranges into your own per-hour numbers.
Rehearse the plan in training, then race it. Order now, ships Australia-wide.
Race week and race day timeline
2 to 3 days out
Carb load toward 8 to 10g per kg per day with low fibre in the final day.
Race morning, 3 hours out
Familiar carbohydrate breakfast, 1 to 2g per kg.
25 to 40 minutes out
One serve of PRIMER: 29g of carbohydrate and 1,313mg of sodium.
From 30 minutes in
CORE on schedule. Take it on sheltered sections, not into the teeth of a headwind.
Final 12km
If the wind turned, hold the fuelling rate rather than dropping it with your pace.
Frequently asked questions
Does wind change how much I should eat in a marathon?
Yes. A headwind raises the energy cost of holding pace, and that cost is largely carbohydrate. On a breezy day, plan toward the upper end of your carbohydrate range and keep intake steady even if your pace slows.
How much sodium do I need in a cool marathon?
Cool conditions reduce but do not remove sweat losses. Most runners still need 300 to 800mg of sodium per hour. Measure your sweat rate rather than assuming a cool day means low losses.
When should I start fuelling at Perth?
By the 30-minute mark, then at regular intervals. Waiting until you feel low means you are already running a deficit that is very hard to repay at marathon pace.
What is the best drink mix for a marathon?
One that delivers dual-carb fuel and meaningful sodium in a concentration your gut tolerates at race pace. HYDRAX CORE provides 85g of dual-carb fuel and 980mg of sodium per serve.
Keep reading
- Marathon fuelling strategy
- Carbs per hour for a marathon
- Carb loading for race day
- Running pace calculator
- Measure your sweat rate
- Shop the HYDRAX kit
Disclaimer: This page is general information for healthy adult athletes and is not medical, dietetic or coaching advice. Individual carbohydrate, fluid and sodium requirements vary with body weight, sweat rate, conditions and health status. Speak with your doctor, sports physician or an accredited sports dietitian before changing your nutrition or supplement routine, rehearse any fuelling plan in training before race day, and always follow the directions and warnings on the product label.