Why do runners use energy drinks for peak performance?

December 21, 2025 •

3 min read

Over 70% of runners participating in a recent study reported using some form of sports nutrition product, including energy drinks, to fuel their training and races. The key reason why do runners use energy drinks is to replenish vital carbohydrates and electrolytes, helping them sustain energy and hydration during long or intense efforts.

Quick Summary

Runners rely on energy drinks to replenish carbohydrates for sustained energy, replace electrolytes lost through sweat, and improve mental focus during endurance activities. They are a convenient fuel source for training and races lasting over an hour.

Key Points

Replenishes Carbohydrates: Energy drinks provide a fast, convenient source of simple and complex carbohydrates to replenish muscle glycogen stores during long runs.
Replaces Electrolytes: They contain vital electrolytes like sodium and potassium, helping to maintain hydration and prevent muscle cramps caused by sweat loss.
Enhances Mental Focus: The caffeine in many energy drinks can boost mental alertness and reduce the perception of effort, especially during the later stages of a race.
Prevents Hyponatremia: Using electrolyte-fortified drinks instead of plain water during marathons helps prevent a dangerous dilution of sodium in the blood.
Offers Convenient Fueling: Energy drinks are easy to consume on the go and can be less likely to cause stomach distress for some runners compared to solid foods.
Aids in Recovery: Hypertonic sports drinks with a higher carb concentration can be used post-workout to help replenish glycogen stores quickly.

Fueling the Marathon: The Science Behind Running Energy Drinks

For endurance athletes, particularly long-distance runners, proper fueling and hydration are critical for success. While a balanced diet forms the foundation, the convenience and specific composition of energy drinks make them a valuable tool for maintaining peak performance during prolonged exercise. These beverages offer a quick, easily digestible source of carbohydrates, electrolytes, and sometimes caffeine to combat fatigue, prevent dehydration, and avoid 'hitting the wall'.

The Role of Carbohydrates

During intense or prolonged exercise, the body's primary energy source is glycogen, which is stored in the muscles and liver. After about 60 to 90 minutes of continuous running, these glycogen stores become depleted. Energy drinks, with their high concentration of simple and complex carbohydrates (like maltodextrin and fructose), provide a rapid and sustained release of energy to replenish these stores and keep the runner going.

Simple Carbs: Offer a quick burst of energy for immediate use.
Complex Carbs: Provide a slower, more sustained release of energy to prevent energy crashes.
Optimized Ratio: Many sports energy drinks use a blend of maltodextrin and fructose, as this combination allows the body to absorb more carbs per hour than a single source, reducing the risk of stomach issues.

The Importance of Electrolytes

Sweating is the body's natural cooling mechanism, but it also causes a significant loss of electrolytes, such as sodium and potassium. These minerals are vital for nerve function, muscle contraction, and maintaining proper fluid balance. Replacing them is crucial to prevent muscle cramps, fatigue, and the dangerous condition of hyponatremia (dangerously low sodium levels from over-consuming plain water). Energy drinks often include these electrolytes to help runners rehydrate more effectively than water alone.

The Caffeine Advantage

For some runners, caffeine offers a legal and effective performance boost. The stimulating effects of caffeine can help improve mental focus, reduce the perception of effort, and increase alertness during the later stages of a long run or race. It's important for runners to test caffeinated products during training, as caffeine tolerance varies and can cause stomach upset or jitters in some individuals.

Types of Energy Drinks and Their Uses

Energy drinks for runners are not one-size-fits-all. They are often categorized based on their concentration relative to the human body, known as tonicity, which affects how quickly they are absorbed.

A Comparison of Running Drink Types


Drink Type	Tonicity	Main Function	Best For	Considerations
Hypotonic	Lower concentration of sugars and salts than blood.	Rapid hydration.	Hot weather, short distances (under 60 min) or for rapid fluid replacement.	May not provide enough carbohydrates for long runs.
Isotonic	Similar concentration of sugars and salts as blood.	Balanced hydration and energy.	General use during most endurance runs (over 60 min).	Provides effective fueling and hydration for typical distances.
Hypertonic	Higher concentration of sugars and salts than blood.	High-carb fueling.	Longer races (ultra-marathons) or as a post-run recovery drink.	Slower absorption; may cause stomach upset if consumed too quickly during intense running.

Putting it all together

Runners use energy drinks strategically, not as a daily beverage. Timing is crucial for maximum benefit. For runs lasting over an hour, it's recommended to start fueling from the beginning, consuming 30–90 grams of carbohydrates per hour. Many runners also find it beneficial to 'pre-load' by taking an energy drink about an hour before a long event, giving the body time to process the carbs. Ultimately, runners must experiment during training to find the right drink type, flavor, and timing that works best for their individual needs and stomach sensitivity. This practice prevents surprises and discomfort on race day and allows them to perform at their best.

Conclusion: A Performance-Enhancing Tool

In conclusion, the primary reason why do runners use energy drinks is to strategically enhance performance by providing essential fuel and hydration. These drinks are a convenient, rapid source of carbohydrates to prevent glycogen depletion and a quick way to replace electrolytes lost through sweat. While not a substitute for a balanced diet and adequate rest, the careful integration of energy drinks into a runner's fueling strategy can make a significant difference in energy levels, endurance, and overall race-day success.

Explore the latest research on caffeine and athletic performance to learn more about the ergogenic effects in sports.

Frequently Asked Questions

Energy drinks, typically high in caffeine and sugar, focus on mental and physical stimulation. Sports drinks, which are what runners use, are specifically formulated with carbohydrates and electrolytes to provide energy and replace lost fluids during exercise, with some varieties including a moderate amount of caffeine.

For runs or intense exercise lasting over 60 minutes, runners should begin consuming an energy drink early and continue to sip it every hour to maintain energy levels. A small amount can also be consumed about an hour before a run to pre-load carbohydrates.

The recommended intake is typically 30–90 grams of carbohydrates per hour during exercise, depending on the intensity and duration. The amount of energy drink needed will vary based on its carbohydrate content.

For runs lasting less than an hour, plain water is generally sufficient for hydration and energy needs. Your body's stored glycogen is usually enough to power these shorter efforts.

Caffeine can benefit performance by improving focus and alertness, but individual tolerance varies. It's crucial to test caffeinated drinks during training, as they can cause stomach upset or anxiety in some people.

'Hitting the wall' is the severe fatigue and exhaustion that occurs when muscle glycogen stores are depleted during endurance running. Energy drinks, by providing a quick and steady supply of carbohydrates, help replenish these stores and prevent or delay this from happening.

Consider the duration and intensity of your run. For long distances, isotonic drinks are a balanced option. For hotter weather, hypotonic drinks offer faster hydration. Ultimately, you must test different products during training to find what best suits your digestion and performance.