A half Ironman is long enough that fuelling decides the outcome and short enough that you race it hard the whole way. That combination is why 70.3 athletes so often ride a strong bike split then run 20 to 30 seconds per kilometre slower than their open half marathon pace.
Sunshine Coast adds warm coastal conditions and an exposed run. The bike is where your fuel goes in, the run is where the bill arrives, and sodium is the variable most athletes under-plan.
What the race demands
Distance
1.9km swim, 90km bike, 21.1km run
Conditions
Warm coastal Queensland with an exposed run course
Main risk
Under-fuelling the bike and losing the run split
Second risk
Sodium losses outpacing intake in the heat
Carbohydrate and sodium targets
- Bike leg: 70 to 90g of carbohydrate per hour from a dual-carb source
- Run leg: 60 to 80g of carbohydrate per hour, taken in small frequent doses
- Sodium: 500 to 1,000mg per hour, higher for salty and heavy sweaters
- Fluid: set by your measured sweat rate rather than thirst
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 days out
Raise carbohydrate intake, drop fibre and anything unfamiliar.
Race morning, 3 hours out
Rehearsed carbohydrate breakfast at 1 to 2g per kg with sodium in your fluid.
25 to 40 minutes pre-swim
One serve of PRIMER: 29g of carbohydrate and 1,313mg of sodium before the swim blackout.
Bike, 90km
Take carbohydrate on a timer from the first 10 minutes. This is your only real fuelling window at 70.3.
Run, 21.1km
Keep carbohydrate coming in small doses from the first aid station. The half marathon is won by the athlete who fuelled the bike properly.
Frequently asked questions
How many carbs per hour for a half Ironman?
Most well-trained 70.3 athletes target 70 to 90g of carbohydrate per hour on the bike from a dual-carb source and 60 to 80g per hour on the run. Gut training in long sessions is what makes the upper end possible.
How much sodium do I need at 70.3 Sunshine Coast?
Warm coastal conditions push most athletes to 500 to 1,000mg of sodium per hour, with salty and heavy sweaters higher again. Measure your sweat rate in similar conditions instead of guessing.
Should I fuel the swim?
You cannot fuel during the swim, which is exactly why the pre-race serve matters. Take carbohydrate and sodium 25 to 40 minutes before the start so you exit the water already topped up.
Why does my 70.3 run fall apart?
Almost always a bike fuelling shortfall, a sodium deficit, or a bike ridden above the effort you trained for. Fix the bike leg and the run usually fixes itself.
Keep reading
- Ironman 70.3 nutrition guide
- Full Ironman nutrition guide
- Carbs per hour for Ironman
- Triathlon time 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.