Carbs in a bottle: The Ultimate Guide to Fueling with Carb Powders

Carbs in a bottle: The Ultimate Guide to Fueling with Carb Powders

Ole
written by
Ole
May 15, 2025

1. Why Carbs Are Essential in Endurance Sports

🔬 Energy Metabolism 101

During endurance activities, your body gets its fuel from two main sources: fats and carbohydrates. While both are important, carbs play a leading role—especially when training gets tough.

Carbohydrates are the body's preferred fuel because they:

  • Convert to energy (ATP) faster than fat

  • Require less oxygen per ATP unit

  • Stay available even at high intensity, where fat becomes inefficient

⚡ Intensity Determines Fuel Use

<Table

columns={[

{ Header: 'Training Zone', accessor: 'zone' },

{ Header: 'Intensity (%VO₂max)', accessor: 'intensity' },

{ Header: 'Main Energy Source', accessor: 'source' },

]}

data={[

{ zone: 'Base / Z2', intensity: '<65 %', source: 'Mostly fat, little carbs' },

{ zone: 'Tempo / Z3–Z4', intensity: '65–85 %', source: 'Mix of fat and carbs' },

{ zone: 'Race Pace / VO₂max', intensity: '>85 %', source: 'Almost entirely carbs' },

]}

/>

As intensity rises, fat metabolism slows. Carbs become your only option for rapid, high-output energy.


🧬 Glycogen: Small Tank, Big Role

Glycogen is how your body stores carbs—in muscles (≈ 300–400 g) and the liver (≈ 100 g). During hard efforts, these stores can run low in 60–90 minutes.

Without external carbs, you risk:

  • Bonking (energy crash)

  • Loss of coordination and focus

  • Weaker immune system post-workout


🍭 Why You Need a Carb Mix

Your body absorbs different carbs through different gut transporters:

  • Glucose / Maltodextrin → via GLUT-2

  • Fructose → via GLUT-5

These work in parallel. If you only take glucose, your absorption maxes out at ~60 g/h. Beyond that: stomach trouble.

But a Glucose + Fructose mix can push that to 90–120 g/h with proper gut training.

That’s why top sports nutrition uses blends of carbs: better absorption, better performance, fewer gut issues.


2. Types of Carbs – Fast vs. Slow

a) Fast Carbs (For Racing)

<Table

columns={[

{ Header: 'Type', accessor: 'type' },

{ Header: 'Effect', accessor: 'effect' },

{ Header: 'Example Use', accessor: 'use' },

]}

data={[

{ type: 'Maltodextrin', effect: 'Glucose-like, but gentler on gut', use: 'Criteriums, races' },

{ type: 'Fructose', effect: 'Uses a different gut pathway', use: 'Gran Fondos' },

]}

/>

🧠 Pro Tip: Maltodextrin + Fructose = “Double Turbo”


b) Slow Carbs (For Long Rides)

<Table

columns={[

{ Header: 'Type', accessor: 'type' },

{ Header: 'Duration', accessor: 'duration' },

{ Header: 'Ideal for', accessor: 'ideal' },

]}

data={[

{ type: 'Isomaltulose', duration: '2–3 hours', ideal: 'Zone 2 training' },

{ type: 'Waxy Maize Starch', duration: '1–2 hours', ideal: '100 km rides' },

]}

/>

👉 Start with Isomaltulose—easy on the stomach!


3. How Much Do You Need?

Step-by-Step Formula

  1. Weigh yourself (e.g., 70 kg)

  2. Choose your effort level:

  • Easy (can chat): 0.5–1.0 g/kg

  • Moderate (breathless, but can talk): 1.0–1.5 g/kg

  • Hard (no talking): 1.5–2.0 g/kg

🧮 Example (70 kg, moderate): 70 × 1.0 = 70 g carbs/hour

IMG_1798

60 gram carbs on 500ml

4. Two Key Carb Mixes

a) Race Mix – For All-Out Efforts

Per 100 g powder:

  • 53 g Maltodextrin

  • 43 g Fructose

  • 4 g Electrolytes (Na, K, Mg, Ca)

Use for: Races, intervals, max efforts

🎉 Flavor Tip: Add granulated iced tea for a budget boost!


b) Endurance Mix – For Long, Steady Rides

Per 100 g powder:

  • 86 g Isomaltulose

  • 8 g Maltodextrin

  • 4 g Electrolytes (Na, K, Mg, Ca)

Use for: Long Z2 sessions, casual Sunday rides

🎉 Flavor Tip: Granulated iced tea also works great here!


5. Gut Training: Don’t Shock Your Stomach

<Table

columns={[

{ Header: 'Week', accessor: 'week' },

{ Header: 'Carbs per Hour', accessor: 'carbs' },

{ Header: 'Goal', accessor: 'goal' },

]}

data={[

{ week: '1–2', carbs: '30 g', goal: 'Build tolerance' },

{ week: '3–4', carbs: '45 g', goal: 'Increase gradually' },

{ week: '5+', carbs: '60+ g', goal: 'Race-ready gut' },

]}

/>

🧪 Always test during training—not on race day!

DIY Starter Mix:

  • 50 g Maltodextrin

  • 50 g Isomaltulose

  • Pinch of salt

  • Mix with 500 ml water


6. Avoid These Common Mistakes

  • ❌ “I’ll just use table sugar” → sugar crash + gut issues

  • ❌ “More is better” → > 60 g/h without gut training = stomach pain

  • ❌ “I forgot electrolytes” → cramps incoming!


7. First-Time Checklist

✅ Mix a light solution (e.g., 30 g Maltodextrin + 500 ml water)

✅ Try on an easy ride (not a race!)

✅ Listen to your gut

✅ After 1 hour, ask: Energy OK? Any discomfort?

“Train your gut like you train your legs.”


8. Science Made Simple

  • Race Mix: Dual carb pathways (2-lane highway)

  • Endurance Mix: Steady release (drip-feed IV)

📚 Fun Fact: Elite athletes can absorb up to 120 g carbs/hour—most should start at 30–40 g/h.


Final Thoughts

  • Start small, mix smart

  • Progress week by week

  • Customize based on your gut

“The best carb mix means nothing if your stomach quits. Be patient—fuel smart.”

You Might Also Like

Review: Abus GameChanger 2.0

Review: Abus GameChanger 2.0

In this blog post I share my experiences with the Abus GameChanger 2.0 helmet. It’s certainly one of the most widespread aero helmets.

read more →

Cervelo S5 in Iron Oxide: Ein Leistungsstarkes Rennrad im Detail

Cervelo S5 in Iron Oxide: Ein Leistungsstarkes Rennrad im Detail

In diesem Blogartikel teile ich meine Erfahrungen mit dem Cervelo S5 in Iron Oxide. Dieses Rennrad beeindruckt mit seiner Ausstattung bestehend aus Re...

read more →

A Hommage to Our Hometown: A List of Group Rides in Münster, Germany

A Hommage to Our Hometown: A List of Group Rides in Münster, Germany

In this article we want to share with you all grouprides in our hometown of Muenster. The cycling community is incredible here!

read more →

Stay Updated with New Articles