Sweatr blog
The science behind performing on race day
Guides, deep-dives, and practical advice for runners, cyclists, and triathletes who want to get their fueling right.
Most Marathoners Fuel at a Third of What They Need
Research shows the average marathoner takes in just 21g of carbs per hour. The target is 60–90g. Here's how to close the gap.
Stop Googling Your Marathon Fueling Plan
Every marathon nutrition guide gives the same generic ranges. Here's why they fail and how to find your actual numbers.
The Off-Season Fueling Experiment: How to Find Your Race-Day Numbers Before Spring Training Starts
Use the off-season to test your carb ceiling, sweat rate, and gel tolerance so your spring marathon plan is built on data.
The Calorie Myth That Makes Marathoners Undereat on Race Day
Your watch says 3,000 calories burned. Stop trying to replace them. Think carbs per hour instead.
Racing Twice This Fall? How to Fuel the Gap Between Back-to-Back Marathons
A fueling and hydration recovery plan for the 3–5 weeks between fall marathons like Chicago and NYC.
Road Fueling Rules Don't Work on Trails — How to Build a Trail Race Nutrition Plan
Trail races break every road marathon fueling rule. Here's how to build a nutrition plan that handles elevation, real food, and hours on your feet.
Your Race-Day Fueling Plan Will Break — Here's How to Fix It Mid-Race
Every fueling plan meets reality at some point. Here are 5 common mid-race fueling failures and exactly how to adapt on the fly.
Your Stomach Turned at Mile 15 — Here's What to Do Next
A mid-race GI survival guide for marathoners: what to do when nausea hits, and how to stop it happening again.
Running Slower Than Planned? How to Adjust Your Fueling Mid-Race
Your marathon pace slipped. Here's how to recalculate your gel timing, carb targets, and hydration on the fly.
Why Gels Make You Sick After Mile 15 — and How to Keep Fueling When Your Stomach Shuts Down
GI distress wrecks more marathons than bad training. Here's why your gut rebels late in a race and what to do about it.
The Absorption Gap: Why Eating Enough Carbs Still Left You Bonking
You followed the fueling plan and still hit the wall. The problem isn't how much you ate — it's how much your body actually absorbed.
Slow Carbs, Fast Carbs, and the Timing Switch Every Endurance Athlete Gets Wrong
The type of carbohydrate you eat matters as much as the amount — and the right type changes as race day approaches.
Your Fueling Plan at 40 Isn't Your Fueling Plan at 30
How age changes marathon nutrition — and what to adjust so your race-day plan works with your body, not against it.
Your Gut Is Why Your Marathon Fueling Plan Fails — Here's How to Fix It in 4 Weeks
A progressive gut training protocol that teaches your stomach to absorb race-day carbs without GI distress.
How to Gut-Train for Your Fall Marathon: A 4-Week Protocol
A week-by-week gut training plan that builds your carb tolerance so race day fueling actually works.
Fasted Training and Race Day Fueling: What Running on Empty Teaches Your Body
Should you train fasted for your marathon? Here's what the science says — and what your watch data reveals.
Why Your Gels Aren't Working: How Hydration Mistakes Sabotage Your Fueling Plan
Most gel problems aren't about the gel. Fix the hydration mistakes wrecking your race-day fueling.
Why You Bonked at Mile 18: The Fueling Mistake That Starts Hours Earlier
The real reason you hit the wall wasn't a missed gel at mile 15. Here's what actually happens — and how to fix it for your fall race.
How to Read Your Body's Fuel Gauge Mid-Run: 7 Warning Signs You're Running Low
Learn to spot the early signs of bonking, dehydration, and overheating before they wreck your race — and how to rescue the run.
How to Fuel Your First 50K: The Ultramarathon Nutrition Plan That Starts With Your Watch Data
Your marathon fueling plan won't work for a 50K. Here's how to build an ultra nutrition strategy using your wearable data.
Why Your Running Buddy's Fueling Plan Won't Work for You
Copying someone else's marathon nutrition is a gamble. Here's why fueling is personal and how to build a plan from your own data.
How Hills Change Your Marathon Fueling Plan
Hilly courses burn more carbs, shift your pacing, and change when you can take gels. Here's how to adjust.
Why AI-Generated Marathon Nutrition Plans Get It Wrong
ChatGPT can write a plausible fueling plan in seconds. Here's why it misses the data that actually matters on race day.
How Much Fuel Do You Actually Need? A Body-Weight-Based Guide to Marathon Nutrition
Stop guessing with the 60-90g/hour range. Calculate your personal fueling target based on body weight, pace, and conditions.
Morning vs Evening Training: Why the Time You Run Changes How Much You Need to Fuel
Glycogen, cortisol, and sweat rate all shift by time of day. Here's how to adjust your fueling.
Why Your First 30 Minutes of Fueling Decide the Last 10K of Your Marathon
Start fueling early or pay later. Here's why the first 30 minutes of your marathon set up the last 10K.
Half Ironman Fueling: The Complete Nutrition Plan From Swim to Finish Line
A leg-by-leg 70.3 nutrition plan with exact gram targets, timing cues, and the bike mistake that wrecks your run.
Why Pace — Not Just Duration — Decides How Much Fuel You Need
Your marathon fueling calculator ignores the biggest variable. Here's why pace changes your carb burn rate — and how to get the number right.
Stop Taking a Full Gel Every 45 Minutes
Smaller, more frequent gel doses reduce nausea and keep energy steadier. Here's how to find your personal rhythm.
How to Fuel Back-to-Back Training Days — The Glycogen Debt Most Runners Ignore
Your Saturday long run empties the tank. Here's how to refuel so Sunday's session doesn't wreck your week.
How to Fuel Long Runs When Your Appetite Disappears in Summer Heat
Heat kills your appetite but raises your carb needs. Here's how to get fuel in when your body doesn't want it.
You're Running a 4:30 Marathon. You Need More Fuel, Not Less.
Slower marathoners spend longer on course, so total fuel demand equals or exceeds faster runners. Here's how to fuel properly.
First Marathon Fueling Guide: What to Eat Before, During, and After Your Race
A complete fueling plan for first-time marathoners — what to eat, when to eat it, and how to avoid the wall.
What to Eat After a Long Run
The 60-minute recovery window most runners miss — what to eat, when, and how much based on your actual effort.
How to Fuel Easy Runs, Speed Work, and Long Runs — Why One Plan Doesn't Fit Every Workout
Your training fueling should change with each workout type. Here's exactly what to eat and drink for easy runs, tempo sessions, and long runs.
Drink Mix, Gels, or Both: How to Build Your Race-Day Fuel Stack
High-carb drink mixes are changing race fueling. Learn when to use drink mix, gels, or both to hit your carb targets without GI distress.
Your fueling plan should change every month of marathon training
Training load, heat, and fitness shift your carb and fluid needs. Here's how to adjust each month.
Your Triathlon Run Fell Apart — Trace It Back to the Bike
Most triathlon run blowups start on the bike. Here's how to fix your bike nutrition so the run doesn't fall apart.
Glucose, Fructose, and Maltodextrin: Why the Type of Carb in Your Gel Matters More Than You Think
Most runners count grams per hour but ignore carb type. Here's how glucose-to-fructose ratios set your absorption ceiling.
Stop Guessing Your Race Nutrition: How to Build a Fueling Plan That's Actually Yours
Every guide gives you ranges. Here's how to find your actual sweat rate, carb ceiling, and sodium needs.
How to Fuel a Century Ride: A Cyclist's Complete Nutrition Plan for 100 Miles
A practical fueling and hydration plan for your century ride — carb targets, fluid timing, and what to carry for 100 miles.
The 120g Carbs Per Hour Claim: What the Science Actually Shows
Everyone's talking about 120g carbs per hour. Here's what the research really says and how to find the number that works for you.
Caffeine in Your Racing Gels: How Much Helps, When to Take It, and When to Skip It
A practical guide to caffeine dosing and timing in racing gels so you get the boost without the gut bomb.
How to Find Your Personal Carb Ceiling — Why 90g Per Hour Isn't Right for Everyone
The 60-90g carb advice is too vague. Here's how to find the number that actually works for your body, pace, and race distance.
Do You Even Need Gels for a Half Marathon?
A first-timer's honest guide to whether you need gels, how many, and when to take them during your half marathon.
Hydrogels, Isotonic Gels, and Traditional Gels: Which One Should You Race With?
A science-backed comparison of the three main gel types to help you pick the right fuel for your next race.
Fueling a 3-Hour vs 5-Hour Marathon: Why One Plan Doesn't Fit All
A 5-hour marathoner needs a completely different fueling strategy than a 3-hour runner. Here's exactly how pace changes everything.
How to Train Your Gut to Handle 90g of Carbs Per Hour
A 12-week protocol to build carb tolerance for race day so you can fuel harder without GI distress.
115 Grams Per Hour: What Sawe's Sub-2 Marathon Teaches You About Fueling
Sawe fueled his 1:59 marathon on 115g carbs/hour. Here's what his protocol reveals about building your own race-day fueling plan.
Real Food vs Gels: What Should You Actually Fuel With on Race Day?
Gels aren't the only option. Here's how to choose between real food and gels based on your pace, distance, and stomach.
The 3 Biggest Nutrition Mistakes Runners Make in the Final 3 Weeks Before a Marathon
Most marathoners sabotage race day before the gun fires. Avoid these three taper-phase nutrition mistakes.
How to Fuel a Half Marathon: The Complete Plan by Finishing Time
Your half marathon fueling plan depends on your pace, not generic advice. Here's exactly what to eat and drink by finishing time.
You Bonked at Mile 22 Despite a Fueling Plan — Here's What Went Wrong
Had a fueling plan and still hit the wall? These five mistakes explain why — and how to fix them before your next race.
Why Your Energy Gels Make You Feel Sick — And How to Fix It
Gel nausea isn't about the brand. It's about timing, carb load, and a gut that hasn't been trained. Here's the science and the fix.
How Many Gels Per Hour Do You Actually Need? A Marathon Fueling Plan by Finishing Time
Generic gel advice ignores your finishing time. Here is a per-hour fueling plan for sub-3 to 5-hour marathoners — plus why slower runners need more, not less.
Why Do Gels Make You Feel Sick? How to Train Your Gut for Race Day
GI distress ruins more races than tired legs. Here's the science behind gel nausea and a practical gut training protocol.
When to take your first gel during a marathon
Most runners take gels too late, wait too long between them, and end up bonking despite carrying the right number. Here's the timing strategy that actually works.