The Science of Hourly Intake in a Long-Distance Cycling Nutrition Plan

Many amateur cyclists often hit “the Bonk” after completing rides longer than 3 hours—a state where the body’s glycogen stores are depleted. This situation can be entirely prevented through a scientific nutrition plan. This article will detail the hourly energy intake strategy for long-distance cycling.

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Why Do We “Bonk”?

The body’s glycogen storage capacity is limited, with muscles and the liver holding approximately 300-500 grams of glycogen combined, equivalent to about 1200-2000 kcal. When riding at high intensity (above 75% of FTP), glycogen consumption can reach as high as 500-800 kcal per hour.

Without timely refueling, you may enter the “bonk” state after 2-3 hours, characterized by:

• A sudden drop in power, making it impossible to maintain previous intensity
• Mental fog and impaired sense of direction
• Legs feeling as heavy as lead

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The Science Behind Hourly Intake

The Upper Limit of Digestion and Absorption

The human gastrointestinal tract has its limits for absorbing different types of carbohydrates:

Carbohydrate Source	Maximum Absorption Rate Per Hour
Glucose	60g
Fructose	30g
Glucose + Fructose (2:1 mix)	90g

This is why modern energy gels and sports drinks often tout the concept of “Multiple Transportable Carbohydrates”—by utilizing different intestinal transport proteins, you can exceed the absorption limit of a single carbohydrate type.

Riding Intensity Determines Needs

Intensity (% FTP)	Energy Requirement (kcal/hr)	Recommended Intake (g carbs/hr)
60-65% (Easy)	400-500	40-50g
70-75% (Moderate)	500-650	50-65g
80-85% (High Intensity)	650-800	60-80g
Above 85% (Race)	800+	80-90g

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A Practical Refueling Schedule

Before the Ride (2 Hours Prior to Departure)

• A high-carbohydrate, low-fat, low-fiber meal (avoid foods that digest slowly)
• Example: White rice (150g) + boiled egg + banana
• Hydration: 500ml

The First 30 Minutes After Departure

Most people don’t need immediate refueling during this period, but for rides exceeding 3 hours, it’s recommended to start your first intake at the 30-minute mark. Don’t wait until you’re hungry to eat.

Hours 1-3 (Refueling Rhythm)

Refuel every 20-30 minutes. Below is a typical 4-hour ride refueling plan example:

Time Point	Refueling Item	Carbohydrate Content
30 minutes	1 energy gel + 200ml water	25g
60 minutes	1 banana	25g
90 minutes	1 energy gel + 300ml electrolyte drink	40g
120 minutes	Rice ball (Japanese-style) or date cake	30g
150 minutes	1 energy bar	40g
180 minutes	1 energy gel + 200ml water	25g

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Comparison of Various Refueling Foods

Energy Gels

Advantages:

• Rapid absorption (effective within 15-20 minutes)
• Easy to carry and space-efficient
• Precise dosing

Disadvantages:

• Overly sweet taste; can cause nausea with prolonged use
• Some brands contain caffeine—use with caution
• Higher cost

Natural Foods (Bananas, Rice Balls, Date Cakes)

Advantages:

• High palatability and strong psychological satisfaction
• Contains trace minerals (bananas are rich in potassium)
• Low cost

Disadvantages:

• Slower digestion
• Inconvenient to carry; may get crushed in the bike bag

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Electrolyte Management

While replenishing carbohydrates, electrolytes (especially sodium) are equally important. When sweating heavily, you can lose 500-2000mg of sodium per hour.

Recommended Electrolyte Intake:

• 400-700mg of sodium per hour
• Can be obtained through salt tablets, sports drinks, or specific energy gels

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Preventing Digestive Issues

Digestive problems are common during long-distance rides. Here are prevention tips:

1. Train your gut: Practice refueling during long training rides to help your body adapt to digesting food while riding
2. Avoid high-fat foods: Fat digests slowly and can cause gastrointestinal discomfort when consumed during a ride
3. Take with water: Always consume energy gels with water to avoid irritating the stomach with overly concentrated solutions
4. Avoid trying new foods: Don’t experiment with untested nutrition products during races or important long rides

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Conclusion

A scientific refueling plan is a crucial foundation for completing long-distance rides. Remember the core principle: Refuel early, refuel often, and don’t wait until you’re hungry. Adjust your intake based on your intensity and the temperature, and continuously test and optimize your personal refueling strategy during regular long training rides.

Related Reading

• Carbohydrate Strategies for Long-Distance Cycling: Hourly Intake and Digestion
• The Complete Guide to Cycling Nutrition: Energy and Hydration Management for Long Rides
• Refueling Strategies for Long-Distance Riding: How Many Carbohydrates Per Hour?
• An Energy Refueling Schedule for Long Rides: Practical Hourly Carbohydrate Intake