Not for the gym. Not for spin class. For the athlete pushing past 90 minutes on the road, track, or trail, where the difference between a good race and a great one comes down to what is in the bottle.
HYDRAX CORE is a dual-carb, high-sodium endurance hydration fuel engineered for the specific demands of long-distance running. No gut bombs. No sugar crash. Just clean, sustained energy and electrolytes that match your effort.
Shop HYDRAX COREMost runners are fueling wrong. Here is why it matters.
Running is deceptively simple. You move forward, you breathe, you repeat. The nutrition looks simple too, until the wheels come off at kilometre 32 and you are wondering why your legs have stopped cooperating.
Only drinking water. Water replaces fluid but not sodium. As you sweat, plasma sodium drops. The result: muscle cramps, cognitive fog, and the kind of fatigue that feels systemic rather than local. Your legs have not failed. Your electrolytes have.
Relying on gels alone for carbohydrates. Most gels deliver glucose or maltodextrin only. Gut absorption is capped at around 60g of carbohydrate per hour from a single-source carbohydrate. If you are running longer than 90 minutes and targeting 60 to 90g per hour, single-source gels cannot absorb fast enough regardless of how many you take. You end up with a gut full of unabsorbed carbohydrate and the GI distress to match. Read drink mix vs gels for a full comparison.
Not enough sodium. Most sports drinks contain 100 to 150mg of sodium per 500ml. Research shows trained runners lose 800 to 1,000mg of sodium per litre of sweat (Baker, 2017). The math does not work. Low-sodium products may maintain hydration volume but they fail to maintain plasma sodium. See how much sodium endurance athletes actually need.
HYDRAX CORE: Fuel that matches how hard you are actually working.
HYDRAX CORE was formulated around one principle: give runners exactly what they need to sustain performance at high effort, for a long time, without the GI distress that derails so many training runs and races.
Dual-carbohydrate formula (maltodextrin + fructose, 2:1)
Maltodextrin is absorbed via SGLT1 in the intestine. Fructose uses a separate transporter, GLUT5. By combining both in a 2:1 ratio, total carbohydrate absorption rises from roughly 60g to up to 90g per hour (Jentjens & Jeukendrup, 2005). The full mechanism is covered in our dual-carb science article.
High-sodium electrolytes
HYDRAX CORE contains significantly more sodium than standard sports drinks, engineered for athletes who lose meaningful sodium through sweat. High sodium maintains plasma volume, supports neuromuscular function, and preserves the thirst drive that keeps you drinking appropriately through a long run.
GI-friendly isotonic formulation
Mixed at the recommended ratio, HYDRAX CORE sits in the isotonic osmolality range, the optimal window for gastric emptying during high-intensity exercise.
Modular by design
Mix lighter for shorter efforts. Mix stronger post-race for rapid recovery. Adjust to match your sweat rate, your event distance, and your gut.
What is in HYDRAX CORE
| Feature | What It Does for Runners |
|---|---|
| HYDRAX PRIMER (pre-run) | 29g dual-carb + 1,313mg sodium 25 to 40 min before your run. Prevents the early blow-up. Shop PRIMER |
| Dual-carb (maltodextrin + fructose, 2:1) | Up to 90g carbohydrate absorption per hour, critical for marathon and beyond |
| High-sodium electrolytes | Replaces sodium lost through sweat; prevents plasma sodium dilution |
| Isotonic formulation | Fast gastric emptying; carbs and electrolytes reach your bloodstream efficiently |
| No artificial stimulants | Sustained energy without crash, stackable with caffeine if desired |
| Modular mixing | Light pre-run, standard in-run, strong post-run, one product with multiple uses |
Dual-carb, high-sodium endurance fuel. Ships Australia-wide.
Shop HYDRAX COREHow to use HYDRAX CORE: Running-specific guide
Short run (under 60 minutes) — No in-run fueling required. Consider one serve of HYDRAX PRIMER 25 to 40 minutes before. High sodium, dual-carb, no stimulants. Loads your system before the effort starts.
Long run (60 to 90 minutes) — Take HYDRAX PRIMER 25 to 40 minutes before your run. Then carry HYDRAX CORE during. Carry a 500ml bottle during the run at standard concentration. Sip every 15 to 20 minutes from around 40 minutes in.
Marathon and race day (90 minutes plus) — Take HYDRAX PRIMER 25 to 40 minutes before the gun. One serve, 300 to 500ml of water. Sodium loaded, carbohydrates primed, nothing that creates GI noise when your heart rate goes through 160. Carry HYDRAX CORE in your race vest or access at aid stations. Target 40 to 60g of carbohydrate per hour from the 40-minute mark. For athletes targeting 90g per hour, use HYDRAX CORE as your primary carbohydrate source alongside gels or chews if needed.
Recovery — Mix a full serving in 500ml water immediately post-run. Fast-absorbing dual carbs begin glycogen resynthesis. High sodium accelerates plasma volume restoration. Follow with a high-protein meal within 90 minutes.
Dial in your own numbers — Fluid and sodium needs are individual, so calculate your sweat rate here, set a realistic goal time with the running pace calculator, then build the hour-by-hour plan in the Fuelling Strategy Engine. For a race-specific version, read our marathon fuelling plan, the Gold Coast Marathon fuelling plan or the Sydney Marathon fuelling plan, the Melbourne Marathon fuelling plan, the Brisbane Marathon fuelling plan or the Perth Marathon fuelling plan, and if you also race longer, the Ironman 70.3 nutrition plan and Ironman nutrition plan follow the same logic.
Between the runs — Hill reps, strength work and back-to-back sessions are where recovery decides your week. Many runners add HYDRAX CREATINE to support repeat-effort output, and single-serve sachets keep the long-run bottle exact without carrying a pouch. You can build your kit here.
For the science underneath the protocol, read the high-carbohydrate fueling strategy, how much sodium you actually need, why osmolality matters for performance and A practical approach to gut training.
Frequently Asked Questions
Dual-carb, high-sodium endurance fuel. Ships Australia-wide.
Shop HYDRAX COREBacked by peer-reviewed sports science. Designed in Australia for Australian conditions.
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.