Carbohydrates in Cycling: Fuel for Maximum Performance

Carbohydrates are the primary energy source for cyclists and form the foundation of every successful nutrition strategy in competitive sports. Optimal carbohydrate supply significantly determines training quality, competition performance, and recovery capacity.

Why Carbohydrates are Essential for Cyclists

Carbohydrates are the preferred fuel for high-intensity efforts, as they occur in cycling. They are stored as glycogen in muscles and liver and are available to the body much faster than fats. During intense efforts over 70 percent of maximum heart rate, carbohydrates are primarily metabolized.

Glycogen Stores and Their Importance

The glycogen stores of a trained athlete comprise approximately 400-600 grams in the muscles and an additional 100-120 grams in the liver. This amount is sufficient for about 90-120 minutes of intense effort. Therefore, strategic carbohydrate intake before, during, and after training or competition is crucial.

Carbohydrate Types and Their Properties

Glycemic Index and Glycemic Load

The glycemic index (GI) describes how quickly a carbohydrate-containing food raises blood sugar levels. The glycemic load additionally considers the actual amount of carbohydrates per serving and thus provides a more practical value for nutrition management.

Carbohydrate Requirements for Cyclists

Timing: When Which Carbohydrates?

3-4 Hours Before Training

Complex carbohydrates with low GI provide stable energy supply without strong blood sugar fluctuations. Ideal are whole grain products, oatmeal, or brown rice combined with moderate protein and fat content.

Example Meal: 100 g oatmeal with banana and nuts, plus whole grain bread with honey (approx. 90-100 g carbohydrates)

60-90 Minutes Before Training

Easily digestible carbohydrates with medium to high GI. The focus is on quick availability without digestive problems during effort.

Example Meal: White bread with jam, ripe bananas, energy bars (approx. 50-70 g carbohydrates)

During Effort (over 90 minutes)

Modern sports nutrition recommends 60-90 grams of carbohydrates per hour during intense efforts. Optimal is a combination of glucose and fructose in a 2:1 ratio, as this utilizes different transport pathways in the intestine and enables higher absorption rates.

Carbohydrate Intake During Long Rides:

• Hour 1: 0-30g CHO (Start with full stores)
• Hour 2: 30-60g CHO (Refilling begins)
• Hour 3-4: 60-90g CHO per hour (Maximum intake)
• Hour 5+: 90g CHO per hour (Maintenance)

Continuous fluid intake parallel across all phases.

Immediately After Training (0-30 minutes)

The "anabolic window" is ideal for fast carbohydrates with high GI in combination with protein (ratio 3:1 to 4:1). This maximizes glycogen resynthesis and initiates recovery processes.

Example: Chocolate milk, protein shake with banana, white bread with honey and quark (approx. 80-100 g carbohydrates + 20-25 g protein)

2-4 Hours After Training

Complete meal with complex carbohydrates, high-quality protein, and healthy fats for complete recovery and replenishment of glycogen stores.

Best Carbohydrate Sources for Cyclists

Carbohydrate Loading (Carbo-Loading)

The classic loading phase begins 3-7 days before an important competition. Modern protocols forgo the earlier "depletion phase" and instead focus directly on continuous increase in carbohydrate intake with simultaneous training reduction.

Carbo-Loading Before Important Competitions:

• Day 1-3: Moderate carbohydrates (5g/kg), intensive training (empty glycogen stores)
• Day 4-5: Increase to 8g/kg, reduced training
• Day 6-7: Maximum 10-12g/kg, minimal training
• Competition Day: 2-3g/kg in the morning, easily digestible
• Result: Optimal glycogen stores: 150-200% normal level achieved

Practical Carbo-Loading Strategy

• Day -3 to -2: 7-8 g carbohydrates per kg body weight
• Day -1: 10-12 g carbohydrates per kg body weight
• Competition Day: 2-3 g carbohydrates per kg in the morning (3-4 hours before start)

Carbohydrates During Different Training Types

Base Endurance (GA1)

During easy rides in the GA1 range (60-75 percent HRmax), the body can use a higher fat percentage for energy production. Nevertheless, 30-50 grams of carbohydrates per hour are recommended for sessions over 2 hours.

Intensive Intervals and Threshold Training

High-intensity sessions require maximum glycogen availability. Recommended are 60-90 grams of carbohydrates per hour during efforts over 90 minutes.

Fasted Training and Low-Carb Strategies

Targeted fasted training can improve fat oxidation capacity. However, this method should only be used for specific GA1 sessions under 90 minutes and not more than 1-2 times per week. Before important training or competitions, fasted training is counterproductive.

Carbohydrate Deficiency: Symptoms and Effects

Typical Symptoms

• Drastic performance drop during effort
• Increased hunger and cravings
• Concentration difficulties
• Muscle tremors and weakness
• Increased susceptibility to infections with chronic deficiency
• Prolonged recovery times

Carbohydrates and Weight Management

Many cyclists struggle with the balancing act between adequate carbohydrate supply and weight optimization. The key lies in strategic timing: High carbohydrate intake around intensive training, moderate amounts on rest days.

Carbohydrate Intake Training vs. Rest Days (75kg Athlete):

• Intensive Training Day: 8-10 g/kg = 600-750 g
• Moderate Training Day: 6-7 g/kg = 450-525 g
• Rest Day: 3-5 g/kg = 225-375 g

Practical Checklist for Optimal Carbohydrate Supply

• Calculate your individual carbohydrate requirement based on training volume and intensity
• Plan main meals 3-4 hours before intensive sessions with complex carbohydrates
• Prepare carbohydrate-rich snacks for training over 90 minutes
• Use the 30-minute post-workout phase for fast glycogen resynthesis
• Combine glucose and fructose for maximum absorption rates during long efforts
• Test your competition nutrition extensively in training
• Keep a nutrition diary to optimize your strategy
• Adjust carbohydrate intake to training and rest days
• Integrate carbo-loading protocols before important competitions
• Pay attention to quality of carbohydrate sources - whole foods in base, fast sources before/during effort

Common Mistakes in Carbohydrate Intake

Too Little During Long Rides

Many athletes underestimate the need during multi-hour training sessions. The consequence: Performance drop, poor recovery, and increased injury risk.

Exclusively Fast Carbohydrates

A diet that only relies on white flour products and sugar leads to blood sugar fluctuations, energy dips, and suboptimal nutrient supply.

Neglecting Post-Workout Timing

Skipping carbohydrate intake in the first 30-60 minutes after intensive sessions significantly slows recovery.

Identical Intake on Training and Rest Days

Rest days with consistently high carbohydrate intake can lead to unwanted weight gain. An adjustment to actual load is sensible.

Carbohydrate Strategies for Different Cycling Disciplines

Road Racing and Grand Tours

Multi-day stage races require consistently high carbohydrate intake (8-12 g/kg daily) to maintain glycogen stores. Professionals take in 90-120 grams of carbohydrates per hour during 5-6 hour races.

Time Trials

For time trials under 60 minutes, full glycogen stores through targeted pre-loading are sufficient. During the race itself, carbohydrate intake is usually not necessary.

Mountain Bike and Cyclocross

The higher intensity variability requires flexible strategies. Recommended are 60-80 grams per hour for races over 90 minutes, preferably in liquid or gel form for easy handling.

Scientific Findings and Current Research

Latest studies show that trained athletes can metabolize up to 120 grams of carbohydrates per hour when an optimal glucose-fructose combination (2:1) is used. This significantly exceeds previous assumptions of a maximum of 60 grams.

Last Update: November 2, 2025