This article delivers a science-backed, step-by-step playbook for timing carbs, sodium and fluids so you can start--and finish--your Hyrox race cramp-free, energized and slosh-free. In it you'll learn how to front-load 8-10 g of carbs per kilo during the final 48 hours, layer in 2,300-3,000 mg of sodium daily, and stagger electrolyte drinks the day before and again 90 minutes out to lock in 20% more endurance while dodging the gut bombs that sink half the field. It maps exact gram targets, urine-color checkpoints and a 3-hour "power plate" (70-80% carbs plus a salt boost) that you scale to your body-weight, test in training, then tweak for early-morning starts or nervous stomachs. Along the way you'll discover why the 2-4 lb water weight gain is a win, how to dodge overhydration, concentrated syrups and NSAIDs, and why personalized sodium balance--not just water--keeps muscles firing at 96% max heart rate. Apply the timeline, track the metrics and you'll stride to the line fully loaded, hydrated and confident your fuel plan is as race-ready as your fitness.
Carb Loading: How Much and When to Eat
Load up with 8-10 g of carbs per kg--about 560-700 g for a 70 kg athlete--during the 36-48 hours before Hyrox to max out glycogen, gain 2-4 lbs of water weight for better hydration, and unlock up to 20% more endurance on race day.
Calculating Your Carb Target per kg
Ready to fuel your Hyrox performance like a champion? Your carb game plan starts with understanding exactly how much fuel your body needs. The magic number is 8-10g of carbs per kg of body weight during the 36-48 hours before race day [1][3]. Don't let the math intimidate you--if you weigh 70kg, that's 560-700g of carbs daily, which sounds like a lot but is totally achievable when you break it down [2].
This strategic carb increase powers up your muscle and liver glycogen stores--think of them as your body's high-octane fuel tanks for crushing those intense Hyrox stations [1]. When fully loaded, these stores can fuel you through 60-90 minutes of high-intensity work before running low [1]. Here's something that might surprise you: gaining 2-4 pounds during carb loading is actually a win! Each gram of carbohydrate brings along about 3 grams of water, creating the perfect hydration setup for race day [2].
This proven protocol can boost your endurance by up to 20%--that's the difference between hitting the wall and powering through to a strong finish [3]. Since most of us only eat 3-6g of carbs per kg on regular days, this increase feels substantial, but trust the process--your body will thank you when you're crushing those sled pushes [1].
Meal Timing 36‑48 Hours Before Race
Your carb-loading journey kicks off 48 hours before race day--think of it as your pre-game power-up phase. The goal remains consistent: 8-10g of carbs per kg daily (as detailed above), but now let's make it happen without overwhelming your system [4].
Here's your game plan: divide your daily carb target across all your eating opportunities. Love three meals and three snacks?
Perfect--just calculate how many grams go into each one.
What to Eat Before Hyrox: Easy Carb‑Rich Options
Now for the fun part--choosing your pre-race fuel! Your main meal 2-4 hours before go-time should feel familiar and comfortable, not like a science experiment [5]. Think of this as feeding your inner athlete with foods that make you feel strong, not stuffed. Love a hearty breakfast? Try protein porridge topped with banana slices and a drizzle of honey, or spread cottage cheese on toast for a creamy, carb-rich option. Bagel lovers, this is your moment--load it up with peanut butter and jam for the perfect fuel combo [5].
More of a savory person? Eggs on toast or chicken sausages tucked into a bagel deliver those essential carbs with satisfying protein [5]. If your stomach tends to be sensitive, keep it light and easy. Pancakes, cereal bars, fruit juice, and dried fruits pack plenty of energy without the heaviness [6]. These options are especially clutch for early morning starts when your appetite might still be snoozing [7]. About 60-90 minutes before showtime, grab one final high-carb snack--roughly 0.
5g per kg of bodyweight keeps the math simple [6]. This could be a banana, an energy bar, or a carb drink--whatever sits well with you. The goal is topping off those fuel tanks without weighing yourself down. Throughout this final prep window, keep sipping on fluids or electrolyte drinks. Small, steady sips beat last-minute chugging every time [7]. (We'll dive deeper into optimal hydration strategies in the sections ahead!
Salt and Electrolyte Strategy for Peak Performance
Dial in 2,300-3,000 mg of sodium daily starting 3-4 days before Hyrox--because nailing your personalized salt strategy keeps muscles firing and brain sharp while station times drop.
Why Sodium Matters in Hyrox
Let's talk about your secret weapon for crushing Hyrox: sodium. This mighty mineral powers everything from muscle contractions to keeping your brain sharp when you're deep in the pain cave. During your 75-90 minute battle through those eight stations, you're going to sweat--a lot. We're talking 1-1. 5 liters per hour, potentially losing up to 10g of sodium [10]. That's like pouring out a whole salt shaker!
Here's what happens when you nail your sodium strategy: Your muscles fire stronger, your mind stays focused, and you power through those brutal sled pushes and sandbag lunges like the devoted athlete you are. Research backs this up--athletes using sodium-rich electrolyte drinks maintain better blood volume and push fatigue away longer than those relying on plain water [10]. The unique challenge of Hyrox? You're constantly switching between running and all-out functional movements, demanding your body to rapidly shift energy systems. Your heart rate stays at about 96% of max throughout [8], and sodium is what keeps everything firing smoothly during these transitions. Here's the kicker: every athlete sweats differently.
Some lose 200mg of sodium per liter of sweat, while others lose up to 2000mg [9]. That's a 10-fold difference! This is why your personalized approach matters. When sodium drops too low, expect muscle cramps, brain fog, and power output that feels like you're moving through molasses. Bottom line? Get your sodium right, and watch your station times drop [8].
Daily Sodium Intake Leading Up to Race Day
Your sodium game plan kicks off 3-4 days before race day--this isn't a last-minute thing. Target 2,300-3,000mg of sodium daily during your final prep days [11]. Yes, that's more than your usual intake, and that's exactly what your body needs as you maintain training intensity before tapering [12]. Build up gradually--don't shock your system by suddenly salt-loading the night before.
Your gut will thank you, and your performance will show it. Make it easy on yourself: sprinkle extra salt on your meals, snack on pickles, or sip tomato juice. These simple swaps boost your sodium without breaking the bank [13]. Pro tip from the devoted: Mix ½ teaspoon of table salt (3.
2g) into 960ml of your favorite sports drink. It creates the perfect electrolyte blend without making it taste like ocean water [13].
Pre‑Race Electrolyte Snacks to Keep You Balanced
Time for your final sodium boost before you hit the starting line. In that crucial 60-90 minute window before go-time, reach for smart electrolyte options: salted pretzels, rice cakes with a generous pinch of salt, or electrolyte chews [14]. These aren't just snacks--they're performance insurance. Early morning start got you stressed?
Liquid electrolytes are your friend. Look for a strong mix that delivers 500mg of sodium per 500ml serving [14]. This preloading strategy is like filling up your reserve tank--you'll have more fluid to draw from when the going gets tough, letting you push harder before dehydration even thinks about slowing you down. Here's a devoted athlete hack: Mix half a teaspoon of table salt into your sports drink for a custom electrolyte blend that actually tastes good [5].
If solid foods feel heavy pre-race, combine tomato juice or your go-to electrolyte drink with simple carbs like salted rice cakes with honey [6]. (For complete pre-race meal ideas that balance carbs and sodium perfectly, check out the Final Plate Assembly section below. ) Remember: You want to start hydrated, not waterlogged. This isn't about panic-drinking at the last second--it's about showing up prepared and ready to dominate [6].
Fluid Intake: Hydration Without the Gut Blowout
Dial in your fluids--sip 500ml of 1,500mg sodium electrolyte 12-16h out, another 500ml 90min pre-start, and top to pale-lemonade urine so you hit the line fully loaded without the slosh.
Baseline Hydration Plan 24 Hours Out
Here's the truth that might surprise you--nearly half of all athletes start their race already behind on hydration [15]. But you're not going to be one of them. Your 24-hour hydration game plan starts now, and we're going to make it simple and achievable. Start increasing your water intake throughout the day before your race, pairing it with the sodium strategies we covered earlier. You're aiming for that perfect pale yellow urine color--think light lemonade, not apple juice or clear water [16]. Add an extra 500-750ml of fluid with each meal to stay on track without feeling waterlogged.
Now here's where you level up: implement an electrolyte preloading protocol that actually works. About 12-16 hours before go-time, down 500ml of a strong electrolyte drink (around 1500mg sodium), then hit another 500ml 90 minutes before your race [15]. This isn't just hydration--it's creating a performance buffer that lets you push harder for longer [15]. Keep tabs on your progress by checking your urine color throughout the day. Dark yellow? You need more fluids.
Completely clear? You might be overdoing it and diluting those crucial electrolytes [16]. Remember, smart hydration isn't about drowning yourself in water--it's about finding that sweet spot between fluids and electrolytes [16]. This 24-hour strategy means you'll toe the starting line fully loaded and ready to dominate, not scrambling to catch up when it's already too late.
Optimizing Fluid Volume 2‑4 Hours Pre‑Start
These final hours are where champions separate themselves from the pack. Your fluid game needs to be on point--aim for 5-10 ml per kilogram of bodyweight (that's about 350-700ml for a 70kg athlete) in the 2-4 hours before you unleash [17][19]. This timing is gold--it gives your body enough runway to process excess fluid while keeping you primed when that starting gun fires. Here's the key: sip, don't chug. Gradually work through your fluids during this window to maximize absorption and avoid that dreaded stomach slosh that kills momentum [18].
Keep using that urine check we talked about--you want pale yellow, like morning sunshine. Crystal clear means you've gone overboard and might have diluted your power-producing electrolytes [19]. Early morning start? No excuses. Begin hydrating the second your feet hit the floor, giving your system time to process before you warm up.
Your drink choice matters too--if your pre-race meal was light on sodium, grab an electrolyte drink. If you salted up your breakfast (like we recommended), plain water works fine [18]. Feeling those pre-race butterflies messing with your stomach? We've got you covered. Liquid nutrition that combines carbs and electrolytes can fuel your hydration needs while being gentle on nervous digestion [17].
Avoiding Common Fluid Pitfalls That Cause Gut Rot
Let's talk about the mistakes that turn strong athletes into bathroom hunters mid-race. Knowledge is power, and we're about to save your race day. The biggest gut bomb? Overhydrating. It's counterintuitive, but drowning yourself in fluids creates more problems than it solves. Research shows that forcing down 1. 4 liters per hour literally doubles your gut discomfort compared to listening to your body and drinking to thirst (around 0. 4 liters per hour) [20].
More isn't always better--it's about being smart. On the flip side, going in dehydrated is equally brutal. It shuts down blood flow to your digestive system, makes your stomach basically stop working, and hello cramping and nausea [20]. Then there's the sneaky culprit--super concentrated carb drinks with osmolalities over 500 mOsm/L that pull fluid into your intestines and create a disaster zone [21]. Here's what else to avoid: popping NSAIDs before racing (they can increase intestinal cramping by 10x! ), letting pre-race anxiety run wild (it directly triggers gut symptoms), and racing in heat you haven't trained for (quadruples your risk of stomach issues) [20]. Your gut-saving game plan? Stick to the hydration strategy you've battle-tested in training.
Choose drinks that won't shock your system. Skip the pain meds. Use breathing techniques or meditation to manage nerves. And if it's going to be hot, make sure you've put in the heat training work beforehand [22]. Remember--every champion has learned these lessons. Now you get to skip the suffering and go straight to performing.
Final Plate Assembly: The Complete Pre‑Hyrox Meal Blueprint
Assemble your 3-hour pre-Hyrox power plate--155g carbs from oatmeal, banana, honey and bagel with salted peanut butter, plus a 500ml electrolyte sip-through--for glycogen-packed, slosh-proof energy that carries you through every station.
Combining Carbs, Salt, and Fluids in One Meal
Ready to bring everything together? Your pre-race meal is where the magic happens--combining the right carbs, salt, and fluids into one powerful plate that'll fuel your Hyrox performance. Think of this meal as your secret weapon: 70-80% carbs for energy, a smart sodium boost for endurance, and strategic hydration to keep you strong through every station. Here's the winning formula: eat your complete meal 3-4 hours before start time--this gives your body the perfect window to digest and convert food into usable energy [23].
For our 70kg example athlete, we're talking about 70-140g of carbs (about 1-2g per kg bodyweight), 500-750mg sodium, and 350-500ml of fluid [24]. As we covered in the carb-loading section, your go-to options remain the same: that trusty porridge with banana and honey, or a bagel with salted peanut butter. The key difference? Now you're adding strategic hydration--sip your electrolyte drink throughout the meal rather than chugging it all at once [23].
Your digestive system will thank you, and you'll avoid that uncomfortable sloshing feeling. Why does this combo work so well? Hyrox demands rapid switches between running and functional movements--your body needs both quick-access energy and stable hydration to power through [23]. This balanced plate delivers exactly that.
Sample 3‑Hour Pre‑Race Plate for Any Athlete
Let's get specific with a proven 3-hour pre-race meal that'll have you crushing those Hyrox stations. Using our 70kg athlete as an example, here's your power plate: The Main Event: - 2 cups of low-fiber oatmeal (60g carbs) made with 250ml milk - Top it with one sliced banana (25g carbs) and 1 tablespoon honey (17g carbs) - Add that crucial pinch of salt (250mg sodium) [5] - One bagel (30g carbs) with 1 tablespoon salted peanut butter (3g carbs, 150mg sodium) [5] - 400-500ml electrolyte drink (20g carbs, 500mg sodium) sipped throughout [25] The Numbers: This champion meal delivers 155g of carbs--that's 2. 2g per kg for our 70kg athlete. Perfect for topping up those glycogen stores without feeling stuffed [6]. The moderate protein keeps your muscles happy without slowing digestion, while the sodium ensures you'll maintain optimal hydration when it counts [25].
The Final Touch: 90 minutes before go-time, grab a small carb boost--a banana or energy bar (25-30g carbs) with another 250ml of electrolyte drink [6]. Make It Yours: Different body weight? No problem! Simply scale the portions: multiply each carb amount by your weight in kg divided by 70. If you weigh 80kg, multiply by 1.
14. If you're 60kg, multiply by 0. 86 [6].
Testing and Tweaking Your Plate for Consistent Results
Here's the truth: your perfect pre-race meal won't happen by accident. The athletes who dominate Hyrox have one thing in common--they've tested and refined their nutrition strategy until it's bulletproof.
Start testing your complete pre-race meal during 2-3 peak training sessions that mirror race intensity [26]. This is where tracking becomes your superpower.
Note everything: how you feel during each station, any stomach issues, your energy levels throughout.
Load 8-10g carbs/kg 36-48h pre-race to max glycogen and boost endurance ~20%.
Gain 2-4lb on carb-load; each gram stores 3g water, priming hydration.
Front-load 2,300-3,000mg sodium daily 3-4 days out to cut cramps and sustain power.
Drink 500ml strong electrolyte (1,500mg Na) 12-16h prior, repeat 90min pre-start.
Eat 1-2g carbs/kg + 500mg Na + 350-500ml fluid 3-4h before start; sip, don't chug.
Skip >1.4L/h fluid, >500 mOsm carb drinks, NSAIDs and last-minute chugging to avert gut rot.
Test the full meal in 2-3 hard training runs; scale portions by body-weight for race-day certainty.