The 24-Hour Ultra-Cycling Nutrition Plan: Fuel Management for Non-Stop Riding

The 24-hour ultra-cycling race is one of the most extreme challenges in endurance sports. Riding non-stop through an entire day and night subjects the body to unprecedented energy expenditure, sleep deprivation, circadian rhythm disruption, and repeated gastrointestinal stress. In such an event, nutrition strategy is not merely a tool for “performance optimization”—it is a determining factor in “whether you can finish at all.”

The Energy Math of a 24-Hour Race

Estimating Total Energy Expenditure

A 65 kg rider sustaining a moderate intensity (approximately 55-65% of FTP) for 24 hours will expend roughly 8,000 to 12,000 kcal in total.

Breakdown:

• Basal metabolic rate (24 hours): approximately 1,600 kcal
• Additional exercise expenditure (24 hours × 350-500 kcal/hour): 8,400-12,000 kcal
• Total: approximately 10,000-13,600 kcal

Even with the most aggressive feeding strategy, it is difficult to consume more than 8,000-10,000 kcal within 24 hours. This means an energy deficit is inevitable; the goal of the strategy is to keep that deficit within an acceptable range.

Carbohydrate Requirements

Riding at a moderate-to-high intensity burns approximately 60-100 grams of carbohydrate per hour. Over 24 hours, this theoretically requires 1,440-2,400 grams of carbohydrates. Muscle and liver glycogen stores hold about 400-600 grams, meaning the remaining 800-1,800 grams must be replenished through in-race intake.

Daytime Phase (Hours 1-12) Nutrition Strategy

Phase 1: Hours 0-4 (Establishing the Rhythm)

State: High energy, elevated adrenaline, normal appetite.

This is the golden window for establishing your fueling rhythm. Your body is at its best, gastrointestinal function is optimal—use this time to maximize carbohydrate intake.

Fueling Plan:

• 60-80 grams of carbohydrate per hour
• Rotate between: sports drinks, energy gels, solid foods
• Eat on a fixed schedule every 30 minutes; set a watch alarm
• Fluid intake: 500-750 ml per hour

Food Choices:

• Mini sandwiches (alternating ham and jam)
• Rice balls
• Energy bars
• Bananas
• Sports drinks

Phase 2: Hours 4-8 (Steady-State Depletion)

State: Initial excitement fades; the pressure of sustained effort begins to set in.

Fueling Plan:

• Maintain 60-80 grams of carbohydrate per hour
• Begin introducing a wider variety of foods to avoid flavor fatigue
• Pay attention to electrolyte intake: 500-1,000 mg of sodium per hour
• Moderate protein (one protein-containing food every 2-3 hours)

Suggested Food Rotation:

• Hour 4: Savory foods (crackers, salted biscuits)
• Hour 5: Sweet foods (energy gels, dried fruit)
• Hour 6: Meal-type foods (small rice balls or sandwiches)
• Hour 7: Liquid carbohydrates as the primary source
• Hour 8: Rotate again

Phase 3: Hours 8-12 (The Turning Point)

State: Fatigue deepens; the first wave of appetite suppression may appear. Nightfall brings psychological pressure.

Fueling Plan:

• Carbohydrate intake may need to drop to 40-60 grams per hour
• Prioritize liquid carbohydrates (easier to absorb when GI tolerance declines)
• First caffeine supplementation (if planned for the latter half)
• Hot beverages begin to provide psychological comfort

Key Warning: Many riders start skipping meals at this point, thinking “if I’m not hungry, I don’t need to eat.” This is the most dangerous mindset. By the time you feel hungry, it is usually already too late.

Nighttime Phase (Hours 12-24) Nutrition Strategy

The Unique Challenges of Nighttime Nutrition

Night riding brings not only visual challenges but also deep physiological changes:

Circadian Rhythm Effects:

• 2-5 AM is the lowest point of the body’s circadian rhythm
• Core body temperature drops
• Insulin sensitivity changes
• Gastrointestinal motility slows
• The appetite center is suppressed

Phase 4: Hours 12-16 (Night Transition)

State: Entering nighttime riding; drowsiness begins to appear.

Fueling Plan:

• Maintain carbohydrates at 40-60 grams per hour
• Significantly increase caffeine intake: 100-200 mg every 3-4 hours
• Introduce hot foods and hot drinks (if support crew is available)
• Savory and spicy foods can help stimulate appetite

Recommended Nighttime Foods:

• Hot soup (chicken soup, miso soup provide sodium and warmth)
• Hot coffee or hot tea
• Salty congee or instant noodles (can be prepared with hot water at aid stations)
• Cola (the perfect combination of carbs + caffeine + comfort)

Phase 5: Hours 16-20 (The Darkest Hour)

State: This is the toughest stretch. Sleep deprivation combined with the cumulative effects of prolonged exercise causes many riders to drop out during this phase.

Fueling Plan:

• Accept that carbohydrate intake may drop to 30-40 grams per hour
• Rely entirely on liquid and semi-liquid foods
• Continue caffeine use but be careful not to overdo it (total 24-hour intake should not exceed 600-800 mg)
• Allow brief stops to eat (this ensures more actual intake than eating while riding)

Survival Eating Strategy:

When you cannot eat according to plan, fall back to this minimum viable strategy:

1. Take at least one sip of sports drink every 20 minutes
2. Consume at least one energy gel per hour
3. Keep fluid intake uninterrupted
4. This is not the optimal strategy, but it will get you through the hardest stretch

Phase 6: Hours 20-24 (Dawn Revival)

State: Daylight brings a massive psychological boost. The body may experience a “second wind.”

Fueling Plan:

• Appetite may return as dawn breaks
• Attempt to restore carbohydrate intake to 50-60 grams per hour
• Final caffeine supplementation at hour 22
• Reduce eating in the final 2 hours and focus on the push to the finish

Gut Management: The 24-Hour Battle to Protect Your Digestive Tract

Preventive Measures

Preparation During Training:

• Practice high-carbohydrate intake during long training rides
• Gradually increase food intake during training sessions
• Test the GI tolerance of all race foods
• Practice eating during nighttime hours

In-Race Prevention:

• Always take energy gels with water
• Avoid overly concentrated carbohydrate solutions (concentration no higher than 8%)
• Eat small amounts frequently rather than large meals
• Alternating cold and hot foods can reduce GI fatigue

Common GI Issues and Countermeasures

Nausea (most common):

• Pause solid foods for 15-30 minutes
• Switch to a very low-concentration carbohydrate drink
• Ginger juice or mint may help
• Reduce riding intensity

Bloating:

• Avoid carbonated drinks (except cola, as it has been degassed)
• Reduce high-FODMAP foods
• Gently massage the abdomen
• Temporarily reduce carbohydrate intake

Complete Inability to Eat:

• This is the most dangerous situation
• Mouth-rinse strategy: rinse with sports drink to stimulate the brain
• Try a completely different type of food (e.g., switch from sweet to savory)
• Consider a brief rest (get off the bike for 5-10 minutes) to let the gut recover

Caffeine Strategy: Managing Wakefulness Over 24 Hours

Caffeine Schedule

Time Period	Caffeine (mg)	Source	Notes
Hours 0-8	0-100	None or small amount of coffee	Save your ammunition
Hours 8-12	100-150	Caffeinated energy gels	Preventive use
Hours 12-16	150-200	Coffee + energy gels	Combat early drowsiness
Hours 16-20	200	Caffeine tablets	Peak effectiveness window
Hours 20-24	100-150	Cola or energy gels	Final push
24-Hour Total	550-800

Caffeine Precautions

• Do not overuse it in the first half; tolerance will build for the latter half
• Caffeine’s half-life is approximately 5-6 hours; caffeine consumed at midnight will still be active by dawn
• If you don’t regularly consume caffeine, the effect will be more pronounced—but so will the side effects
• Caffeine can worsen dehydration and GI discomfort; pair it with adequate fluid intake

Support Crew Nutrition Planning

With a Support Team

For an ideal 24-hour race with crew support, you should prepare:

Fixed Aid Station Food (replenished every 4 hours):

• Fresh sandwiches and rice balls
• Hot soup and hot drinks (at night)
• Energy gels and bars in various flavors
• Fresh fruit (bananas, watermelon, oranges)
• Cola and sports drinks
• Replacement water bottles (pre-mixed with nutrition drinks)

Racing Solo

Pre-Race Checklist:

• 24 energy gels (various flavors)
• 6-8 energy bars
• High-carbohydrate drink powder (enough to mix 10+ bottles)
• Electrolyte powder or tablets
• Caffeine tablets
• Instant coffee packets
• Sealed packets of crackers and nuts

Post-Race Recovery: Repairing After 24 Hours of Punishment

After finishing a 24-hour race, your body is in a state of extreme depletion. Recovery takes days or even weeks.

Immediately After the Race (0-2 Hours)

• Do not eat a large amount right away (your digestive system needs time to recover)
• Start with liquid foods: recovery drinks, juice, soup
• Replenish fluids and electrolytes
• Eat small amounts frequently, trying food every 15-20 minutes

Short-Term Recovery (2-24 Hours)

• Gradually return to a normal diet
• Recovery meals high in carbohydrates and protein
• Adequate sleep is more important than nutrition
• Don’t forget to keep hydrating

Mid-Term Recovery (1-7 Days)

• Consume an extra 500-1000 calories per day to make up for the energy deficit
• Increase anti-inflammatory foods (fish oil, turmeric, berries)
• Avoid alcohol (for at least 48 hours)
• Engage in light activity to promote recovery; don’t stay completely sedentary

Conclusion

Nutrition management for a 24-hour ultra-cycling race is a sustained battle spanning day and night. There is no perfect plan—unexpected situations will always arise. The key is to build a flexible framework: maximize intake when you’re feeling good, maintain a minimum baseline when you’re struggling, and never completely give up on eating at any point. Remember: in a 24-hour race, you’re not chasing optimal nutritional performance; you’re managing the inevitable decline curve, keeping it as gradual as possible.

Related Reading

• 4-Hour Cycling Fueling Plan: A Strategy for Uninterrupted Fuel Throughout the Ride
• Ultramarathon Nutrition Strategies: Energy Supplementation Plans for 24-Hour Races
• Ultra-Endurance Cycling Events: A Complete Preparation Guide for 24-Hour Challenges
• Pre-Race Week Carbohydrate Loading Strategy: Maximizing Glycogen Stores