Fuel smarter. Finish stronger.
Science-backed race nutrition guides for Ironman, 70.3, marathon, half marathon, and ultra athletes. Learn the fueling strategy that prevents the wall — then build your personalized plan.
Why we wrote these guides
Most race-day failures are not fitness failures. They are fueling failures. The athlete trained well, then bonked at mile 18, cramped on the bike at hour four, or threw up the third gel in a row at the hottest stretch of the course. The science of how to prevent that — carbohydrate oxidation rates, gut training, fluid and sodium balance, caffeine timing — is well established. The hard part is translating it into something you can actually do during a race.
That is what this blog is for. Every guide here is built around one specific decision an athlete has to make: how many gels for a marathon, what to eat the night before, when to start fueling on the bike, how to adjust in heat. We pull from peer-reviewed sports nutrition research — Jeukendrup on multi-transportable carbs, Burke on carb periodization, the ACSM and ISSN position stands — and cross-check it against what coaches and athletes actually do on race day. Then we strip out the jargon.
Read the guide that matches your next race, then try one of our free fueling calculators to see your numbers, or build a full minute-by-minute plan for $27 — or get Season Pass at $49/year if you have multiple races.
Triathlon Race Week Nutrition: The 7-Day Countdown to Race Day
Day-by-day nutrition for the 7 days before a 70.3 or 140.6. When to start carb loading, what to eat the night before, and the race-morning T-minus protocol.
3-Day Carb Loading Meal Plan: Exact Meals for Marathon & Triathlon
The complete 3-day carb loading meal plan with gram-per-kg targets, specific meals for breakfast, lunch, and dinner, and what to avoid the night before.
70.3 Fueling Schedule: Exact Carbs, Fluid, and Sodium Per Hour
The complete Ironman 70.3 fueling schedule. Hour-by-hour carb targets (60-90g/hr), fluid strategy, sodium protocol, and T1/T2 nutrition by finish time.
How Many Energy Gels for a Half Marathon? An Exact Count
Exact gel count for a half marathon by finish time. When to take your first gel, spacing strategy, caffeine timing, and what to do when gels cause stomach issues.
How Much Sodium Per Hour for an Ironman? The Electrolyte Guide
Evidence-based sodium targets for Ironman 140.6 and 70.3. How to calculate your personal sweat sodium loss, signs of over and under-salting, and product recommendations.
Race Day Nutrition Plan for a Marathon: Complete Fueling Guide
Your complete marathon race day nutrition plan — exact gel timing by finish time, carb targets per hour, hydration strategy, caffeine timing, and how to avoid the wall from mile 18.
Triathlon Nutrition Calculator: How to Calculate Your Race Day Fueling
Calculate your exact triathlon nutrition needs by race distance, finish time, and body weight. Complete formulas for carbohydrate, fluid, and sodium targets per segment — sprint to full Ironman.
How Many Gels Do You Need for a Marathon? An Exact Count by Finish Time
"A gel every 30 minutes" hides the math. Here is the exact gel count for a 3, 4, or 5-hour marathon, when to take the first one, and what to take it with.
Race-Morning Breakfast: What to Eat 4 Hours Before the Gun
Race-morning breakfast can make or break the first 10K. The exact 4-hour, 2-hour, and 30-minute meal plan for marathon and Ironman race mornings.
The Night-Before Marathon Dinner That Won't Wreck Your Race
The wrong pre-race dinner doesn't just hurt — it can end your race by mile 3. Three exact dinner templates, the 2 g/kg carb formula, and the foods to cut no matter what your coach says.
Caffeine for Endurance: The Exact Dose for Marathon, 70.3, and 140.6
Caffeine can shave 4–10 minutes off a marathon — at the right dose, timing, and habituation level. The full protocol for marathon, half-Ironman, and Ironman.
Hot-Weather Marathon Fueling: How to Adjust the Plan
Above 18°C your fueling plan changes. The exact hot-weather adjustments to carbs, fluid, sodium, and pace so a hot marathon does not become a DNF.
How to Calculate Your Sweat Rate in Under 90 Minutes
The 90-minute sweat-rate test that gives you a personalised hydration target. The exact protocol, the formula, and what your number means for race day.
You Can Drink Too Much Water in a Marathon — Here's Why It's Deadly
Overhydration kills more marathon runners than dehydration. Learn the warning signs, the sodium targets (by hour), and the one rule that prevents the most dangerous mistake on race day.
Bonk Rescue: The 30-Minute Mid-Race Recovery Protocol
You bonked at mile 18. A structured 30-minute protocol can put you back in the race. Carb dose, sodium, walk break, mental cue — exactly what to do.
Never Hit the Wall Again: The 5 Rules That Actually Work
Most runners bonk because of one fixable mistake made before the race even starts. Five rules — backed by research, not bro-science — that keep you running strong through mile 20 and beyond.
Post-Marathon Recovery Nutrition: The First 24 Hours
The 30-minute window, the 4-hour follow-up, and the week-long rebuild. Exactly what — and how much — to eat after a marathon to recover faster.
What to Eat in T1 and T2 (Most Triathletes Get This Wrong)
The gel you grab in T2 might be killing your run. Exact calories, timing windows, and what to skip at each transition for 70.3 and 140.6 — in under 60 seconds of reading.
How to Fuel a Marathon When Your Gut Falls Apart
If gels make you stop at every port-a-potty, your nutrition plan isn't built for you. Safe gel picks, a race-week low-FODMAP meal plan, and a gut-training protocol that actually works for sensitive stomachs.
How Many Carbs Per Hour Do You Actually Need? A Distance-by-Distance Guide
The 60 g/hr ceiling is outdated. Here is the evidence-based carbohydrate target for half marathon, marathon, 70.3, Ironman, and ultra distance events.
How to Carb-Load Before a Marathon: 3-Day Meal Plan
How to carb load: the 3-day protocol with gram-per-kg targets (10-12g/kg/day), best foods, sample meal plan, and what to avoid. For marathon and triathlon.
Runner's Stomach: Why GI Problems Happen on Race Day and How to Train Your Gut
Up to 70% of endurance athletes experience GI distress during racing. Here are the causes, the 8-week gut training protocol, and what to do when it goes wrong mid-race.
Salt, Sodium, and Electrolytes for Endurance Athletes: How Much Do You Actually Need?
Sweat sodium varies fourfold between athletes. Here is how to personalise your electrolyte intake to prevent cramping, hyponatremia, and the bonk that is not actually a bonk.
Real Food vs. Gels for Ultramarathons: What to Eat When Your Stomach Stops Accepting Sweet Fuel
Palate fatigue kills ultra races. Here is how to combine gels and real food across 50K–100 mile events so you are still eating at mile 60.
How to Fuel an Ironman 140.6: A Complete Race-Day Nutrition Guide
The math, the timing, and the protocols behind going 140.6 miles without bonking. From carb loading to mile 18 of the marathon.
How to Fuel a 70.3 Half Ironman: Race-Day Nutrition That Actually Works
Everything you need to know about fueling a 70.3 — carb targets, hydration, timing, and how to avoid the crash that kills your run.
How to Fuel a Marathon: Race-Day Nutrition from Mile 1 to 26.2
The wall is a fueling failure, not a fitness failure. Here is the complete carbohydrate, hydration, and timing strategy that prevents it.
Half Marathon Nutrition: The Complete Race-Day Fueling Guide
Complete half marathon nutrition plan: what to eat the week before, race morning, during the race (gel count by finish time), and recovery. Evidence-based targets.