How to Fuel a HYROX Race: Your Strategy by Finish Time

Your body stores roughly 400 to 600 grams of muscle glycogen at any given time when fully loaded, equivalent to approximately 1,600 to 2,400 calories of carbohydrate energy (Hargreaves and Spriet, 2020). At HYROX intensities (a hybrid of sustained aerobic running and repeated explosive neuromuscular efforts), glycogen depletion rates are higher than for steady-state running.

Research on high-intensity intermittent exercise shows that maximal or near-maximal efforts can deplete local muscle glycogen by 40 to 60% within 15 to 30 minutes, even when total body glycogen reserves remain substantial (Spencer et al., 2005). This means fatigue during HYROX stations is often local glycogen depletion in the working muscles, not systemic energy failure, and it can occur sooner than athletes expect.

The threshold for when exogenous (in-race) carbohydrate becomes performance-relevant is generally accepted as 60 to 75 minutes of sustained high-intensity exercise (Jeukendrup, 2004). Below that threshold, pre-race glycogen loading is sufficient. Above it, in-race carbohydrate progressively matters more.

Who this is for

Elite athletes or experienced HYROX competitors completing the event in under 60 minutes.

The physiology

At sub-60-minute durations, muscle glycogen stores (when properly pre-loaded) are sufficient to sustain performance. The limiting factor is not carbohydrate availability but electrolyte balance, pacing and power output management, and neuromuscular fatigue.

Consuming carbohydrates during the race itself offers minimal performance benefit at this duration, and attempting to drink mid-station introduces unnecessary complexity and risk.

Your fueling plan

24 hours before: Moderate carb loading at 6 to 8g carbohydrate per kg of bodyweight. Focus on easily digestible sources (white rice, pasta, bread, potato, fruit). Reduce fibre intake to minimise GI risk.

Race morning (2 to 3 hours before): 1 to 1.5g carbohydrate per kg of bodyweight (70 to 105g for a 70kg athlete). Simple, familiar food: oats with banana, white toast with jam.

25 to 40 minutes before the race: One serve of HYDRAX PRIMER in 400 to 500ml water. Delivers 29g of fast-absorbing dual carbs as an immediate energy top-up, and 1,313mg of sodium to pre-load plasma volume and support neuromuscular function. Sip over 15 to 20 minutes.

During the race: Nothing. You do not need it. A small sip of water mid-race is fine but not required for performance.

Immediately after: Full serving of HYDRAX CORE in 500ml water. Accelerates glycogen resynthesis and sodium replacement. Follow with a protein-rich meal within 90 minutes.

What sub-60 minute athletes should not do

• Do not carry gels you will not use
• Do not consume a large carbohydrate drink immediately before the gun — a full stomach impairs breathing efficiency
• Do not drink excessive plain water if you have sweated heavily without electrolytes, as this dilutes plasma sodium

Who this is for

The majority of competitive HYROX athletes. This is the most common finish time bracket and the most nuanced fueling category.

The physiology

At 75-plus minutes, glycogen stores begin approaching depletion territory, especially for athletes who have not carb-loaded aggressively. The final two to three stations of HYROX (wall balls, sandbag lunges) are the hardest, and they occur when glycogen reserves are lowest.

A 2004 review by Jeukendrup found that carbohydrate mouth-rinsing alone, without even swallowing the carbohydrate, improved performance in 60-minute time trials. Actually consuming and absorbing carbohydrate produces even greater benefit.

Your fueling plan

36 to 48 hours before: Full carb loading at 7 to 10g carbohydrate per kg of bodyweight. A 20 to 40% increase in muscle glycogen concentration directly delays the onset of fatigue in your final stations.

Race morning (3 to 4 hours before): 1.5 to 2g carbohydrate per kg of bodyweight. Allow sufficient time for digestion.

25 to 40 minutes before the race: One serve of HYDRAX PRIMER in 400 to 500ml water. Pre-loads 1,313mg of sodium plus a fast-acting dual-carb top-up.

During the race (recommended): 500ml bottle of HYDRAX CORE at approximately 6% carbohydrate concentration (roughly 30g carbs, high-sodium). Take 2 to 3 strategic sips in transition zones, ideally between your 4th and 5th run segments around the 40 to 50 minute mark. A single, well-timed 100 to 150ml sip is enough to meaningfully extend your glycogen availability through the back half without causing GI distress.

Immediately after: Full serving of HYDRAX CORE in 500ml water within 30 minutes. High-carb, protein-rich meal within 90 minutes.

Who this is for

Athletes completing HYROX in 90 minutes or beyond, whether a first-time competitor, an athlete returning from injury, or someone competing in age group categories at longer durations.

The physiology

At 90 minutes and beyond, active in-race carbohydrate fueling is not optional. Research consistently demonstrates that carbohydrate ingestion during exercise lasting 90-plus minutes improves performance by 10 to 15% compared to placebo (Burke et al., 2011).

At this duration the dual-carb formulation in HYDRAX CORE becomes particularly important. Single-carbohydrate sources cap absorption at approximately 60g per hour. Adding fructose, which uses a separate transporter (GLUT5), raises the ceiling to 90 to 120g per hour (Jentjens and Jeukendrup, 2005).

Your fueling plan

36 to 48 hours before: Aggressive carb loading at 8 to 10g carbohydrate per kg of bodyweight.

Race morning (3 to 4 hours before): 1.5 to 2g carbohydrate per kg of bodyweight. If nerves suppress appetite, opt for liquid carbohydrates.

25 to 40 minutes before: One full serve of HYDRAX PRIMER in 500ml water. 1,313mg sodium pre-load plus 29g dual-carb fuel before the race clock starts.

During the race: Target 40 to 60g of carbohydrate per hour from approximately 40 minutes in, via a 750ml bottle of HYDRAX CORE at roughly 8% concentration. Take sips in every transition zone. Target 300 to 400mg sodium per 500ml of fluid. Heavy sodium sweaters may add a sodium capsule at the 60-minute mark.

Immediately after: Full serving of HYDRAX CORE in 500ml water within 30 minutes. Protein-rich meal within 90 minutes. Continue hydrating with electrolyte-containing fluid for 4 to 6 hours post-race.