Based on a study with marathon runners published in Sports Medicine Open, which evaluated real intake of carbohydrates, sodium, fluids, and caffeine before and during the race and its relationship with performance.
Carbohydrates at 60 to 90 g per hour, sodium at 300 to 700 mg per hour, hydration at 500 to 1000 mL per hour, and caffeine adjusted by body weight are pillars that sustain pace, reduce fatigue, and help prevent the so called “wall” in events lasting more than two hours.
Average versus recommended intake in marathons
| Nutrient | Observed average | Endurance recommendation | Main impact |
|---|---|---|---|
| Carbohydrates | 35 g per hour | 60 to 90 g per hour | Preserves glycogen, sustains pace |
| Sodium | 192 mg per hour | 300 to 700 mg per hour | Fluid balance, muscle function |
| Fluids | 466 mL per hour | 500 to 1000 mL per hour | Prevents dehydration |
| Caffeine | 57 mg per hour | 30 to 60 mg per hour | Reduces perceived effort |
Why supplementation is decisive in long distance events
Running long distances requires much more than physical preparation. Energy availability, electrolyte balance, and intake strategy throughout the race directly influence performance, fatigue, and the ability to sustain pace until the finish.
Studies with marathon runners show that nutritional intake during the race is directly related to finishing time and performance maintenance throughout the course.
Carbohydrate, the main fuel for running
Carbohydrate is the central nutrient for long duration events. It supports exercise intensity and helps preserve muscle glycogen stores.
Analyses with marathon runners show that athletes who reached carbohydrate intake recommendations during the race had a higher likelihood of better performance, even though average intake remained around 35 g per hour, below the recommended 60 to 90 g per hour.
This reinforces that many runners still underestimate the impact of carbohydrate strategy during the race.
Electrolytes and hydration, far beyond drinking water
Sodium loss through sweat can compromise fluid balance, muscle function, and the absorption of fluids and carbohydrates.
Among marathon runners, average sodium intake was close to 192 mg per hour, below endurance recommendations. Fluid intake also remained near the lower recommended range.
Effective hydration does not mean simply drinking water. It involves strategic electrolyte replacement to support performance, intestinal absorption, and muscle function.
Caffeine as an ergogenic resource
Caffeine reduces perceived effort, improves alertness, and can help maintain intensity during decisive moments of the race.
Average intake observed in marathons is around 57 mg per hour. Practical protocols usually consider intake adjusted by body weight, typically around 3 mg per kg before the start and small additional doses throughout the race, respecting individual tolerance.
The biggest mistake among runners, lack of planning
One of the most consistent findings in studies with runners is that most athletes do not reach carbohydrate, sodium, and fluid intake recommendations during the race.
Factors include lack of nutritional guidance, absence of a defined strategy, and limited practice of intake during training.
Endurance supplementation should not be improvised. It needs to be planned, tested, and adjusted according to individual response.
Supplementation format during the race
The choice depends on race duration, intensity, climate, and athlete preference.
Gels provide carbohydrates in a practical and concentrated form.
Sports drinks contribute to hydration and electrolyte replacement.
Powdered supplements allow concentration adjustments according to needs.
Bars and solid foods can be used at specific moments, depending on gastrointestinal tolerance.
Combining formats is usually the most efficient approach in long distance events.
What defines an efficient strategy
A supplementation strategy should consider
race duration
exercise intensity
sweat rate
gastrointestinal tolerance
athlete experience with intake during exercise
Testing strategies in training reduces risks, improves gastrointestinal adaptation, and increases predictability on race day.
Quick FAQ
Ideal carbohydrate dose in a marathon
60 to 90 g per hour, divided throughout the race.
Gels or sports drinks
Combining both is usually more effective. Gels for concentrated carbohydrates and drinks for hydration and electrolytes.
When to use caffeine
Before the start and at strategic moments during the race, adjusted according to individual tolerance and body weight.
Signs of insufficient intake
Early fatigue, pace drop, muscle discomfort, and difficulty sustaining intensity in the final part of the race.
Supplementation for long distance running is a structured strategy that integrates carbohydrates, electrolytes, hydration, and in some cases caffeine.
Evidence shows that athletes who approach nutritional intake recommendations during the race tend to maintain pace better, reduce fatigue, and present more consistent performance.
The more individualized and tested the plan, the greater the chance of running with stable energy from start to finish.
Costa RJS, Knechtle B, Nikolaidis PT, et al. Nutritional intake and its relationship with performance in marathon runners. Sports Medicine Open. 2024. Available at: https://link.springer.com/article/10.1186/s40798-024-00801-w
