Daily Carb Needs: Why Your Carb Intake Should Increase with Training
As an endurance athlete, you carefully plan your training schedule, progressively increasing mileage and intensity to reach peak performance. But are you fueling your body to match your training load?
One of the biggest mistakes endurance athletes make is not adjusting carbohydrate intake as training volume and/or as intensity increases. Without enough carbs, you risk fatigue, slower recovery, decreased performance, and even increased injury risk.
In this blog, we’ll cover:
Why carbohydrates are essential for endurance training
How to calculate your daily carbohydrate needs based on training intensity
The best carb-rich foods to fuel performance and recovery
Practical tips to fine-tune your fueling strategy
Let’s dive in!
Why Carbs Are Essential for Endurance Athletes
Carbohydrates are the primary fuel source for endurance athletes. While fats and proteins provide some energy, carbs are the most efficient source, fueling both short, high-intensity efforts and long, sustained efforts.
Here’s why carbohydrates matter for endurance athletes:
Primary Energy Source – Carbs are stored as muscle glycogen, which is rapidly converted into energy during exercise.
Improved Performance – Athletes with adequate glycogen stores can sustain higher intensities and experience lower perceived exertion during workouts.
Faster Recovery – Consuming carbs post-workout helps replenish glycogen stores and supports muscle repair when paired with protein.
Prevents Fatigue & Overtraining – Low glycogen levels lead to early fatigue, reduced power output, and increased risk of overuse injuries.
Now that we know why carbs are critical, let’s talk about how much you actually need to perform at your best.
How Many Carbs Do You Need?
Your daily carbohydrate needs depend on training intensity and duration. The more you train, the more carbohydrates you need to fuel your body effectively.
What Do These Carb Numbers Look Like in Real Food?
Let’s break these numbers down into actual meals and snacks.
To hit 400-600g of carbs per day, an athlete might eat:
Breakfast: Bagel with peanut butter + banana (80g carbs)
Lunch: Rice bowl with grilled chicken & veggies (100g carbs)
Dinner: Pasta with marinara sauce & side of garlic bread (120g carbs
Snacks: Greek yogurt + granola (45g carbs), fruit smoothie (60g carbs), handful of pretzels (30g carbs
Pre/Post-Workout Fuel: Sports drink (30g carbs), energy gel (25g carbs), oatmeal with honey (50g carbs)
Total: ~515g carbohydrates
It’s easy to underestimate how many carbs you actually need. If you’re feeling sluggish, struggling to recover, or experiencing increased perceived exertion, it might be a sign you’re not eating enough carbs.
Carb-Rich Foods for Endurance Athletes
To meet your carb needs, focus on a mix of whole foods and quick-digesting carbs around training.
Grains & Breads: Oatmeal, whole wheat bread, bagels, pasta, rice, quinoa
Starchy Veggies: Potatoes, sweet potatoes, corn, squash
Fruits: Bananas, apples, berries, oranges, dried fruit
Cereals & Granola: Whole grain cereals, granola, muesli
Dairy & Dairy Alternatives: Milk, yogurt, kefir
Quick-Digesting Carbs: Sports drinks, gels, honey, fruit juice
Pro Tip: Pair carbs with protein for sustained energy and better recovery. Example: Greek yogurt with granola, or oatmeal with protein powder.
How to Adjust Your Carb Intake as Training Increases
Here’s how to match your carbohydrate intake to your training load:
Off Days / Recovery Days → Stick to moderate carb intake (5g/kg/day).
Easy / Moderate Training Days (~1 hour/day) → Aim for 5-7g/kg/day.
Higher Intensity Days (1-3 hours/day) → Increase to 6-10g/kg/day to fuel workouts and aid recovery.
Peak Training / Race Prep (4+ hours/day) → Your body needs 8-12g/kg/day to sustain high-intensity efforts.
Carb Timing Matters: Spread carbs evenly throughout the day, with an emphasis on pre- and post-workout nutrition for optimal performance.
Common Carb Myths – Busted!
Myth: “Carbs make you gain weight.”
Fact: Carbs are essential for fueling training and maintaining lean muscle. Weight gain occurs from excess calories, not carbs alone.
Myth: “You only need carbs on race day.”
Fact: Carb-loading before race day is helpful, but consistent daily intake is crucial for long-term performance.
Myth: “Low-carb diets are better for endurance athletes.”
Fact: Low-carb diets reduce glycogen stores, making it harder to sustain high-intensity exercise. Most endurance athletes perform best on a high-carb diet.
Are You Eating Enough Carbs?
If you’re experiencing:
Early fatigue in workouts
Slow recovery between sessions
Heavy legs or increased perceived effort
Unintended weight loss or loss of appetite
…You might not be fueling with enough carbs!
Final Thoughts: Train Hard, Fuel Smart
As training increases, so should your carb intake. Don’t let under-fueling hold you back from reaching your potential.
Match your carb intake to your training intensity
Focus on quality carb sources to fuel endurance
Adjust intake as mileage and intensity increase
Need help fine-tuning your nutrition and training to make sure you’re fueling your body for your performance goals?
Book a 1:1 Fueling & Strategy Session to:
Identify gaps in your nutrition & training
Create a personalized fueling plan for stronger bones & better recovery
Get expert guidance on performance nutrition for endurance athletes