What do marathon runners drink before a race?: Hydration Strategies for Peak Performance

October 2, 2025 •

4 min read

Proper hydration is crucial for marathon performance and safety, with some experts recommending that runners drink 16 to 20 ounces of fluid two to three hours before a race. Understanding what do marathon runners drink before a race is a key part of any successful nutrition plan.

Quick Summary

This article details optimal pre-race hydration strategies for marathon runners, covering the best drinks like electrolyte mixes and sports drinks, proper timing, and fluid quantities. It also explains the risks of over-hydration and what beverages to avoid.

Key Points

Electrolyte Drinks are Key: On race day morning, sodium-rich electrolyte drinks are superior to plain water, helping your body retain fluid and supporting cardiovascular function.
Practice During Training: Never try a new hydration strategy on race day. Test different drinks and timing during your long training runs to see what works best for your body.
Timing is Crucial: Hydrate consistently in the days leading up to the race. On race morning, drink fluids 2-3 hours beforehand, and finish your last dose of electrolytes at least 45 minutes before the start.
Avoid Hyponatremia: Gulping large amounts of plain water without electrolytes can dilute your blood's sodium and cause dangerous hyponatremia. Sip steadily instead.
Use Caffeine Wisely: If you are a regular caffeine consumer, a dose 30-60 minutes before the race can enhance performance. Test your caffeine sensitivity during training to avoid stomach issues.
What Not to Drink: Alcohol is a diuretic that negatively impacts performance and recovery. Avoid it in the 24-48 hours before your race.

The Importance of Pre-Race Hydration

Starting a marathon adequately hydrated is fundamental for success. During endurance events, the body sweats to regulate temperature, losing not only water but also essential electrolytes like sodium and potassium. Dehydration can lead to a host of problems, including decreased cardiovascular function, impaired thermoregulation, and accelerated fatigue. However, over-consuming plain water can also be dangerous, potentially leading to a condition called hyponatremia, where the body's sodium levels become dangerously low. A successful pre-race hydration strategy, therefore, involves balancing fluid and electrolyte intake. The process begins days before the event, with athletes consciously increasing their fluid consumption, particularly electrolyte-enhanced fluids, to boost blood plasma volume.

Top Drink Choices for Race Morning

What do marathon runners drink before a race varies, but a few key categories provide the necessary benefits.

Sports Drinks and Electrolyte Mixes

For most endurance runners, especially those expecting to be on the course for more than an hour, sports drinks or electrolyte mixes are the top choice. These beverages are designed to provide a balanced solution of carbohydrates and electrolytes, which helps with both energy and hydration.

Carbohydrates: Drinks with carbohydrates, like glucose and fructose, provide a quick source of energy that is easy for the body to digest during exercise. This helps top off muscle glycogen stores and prevents fatigue from setting in early.
Electrolytes: Sodium is the most critical electrolyte lost through sweat, and consuming it helps the body retain fluid more effectively and supports proper muscle function. Popular brands like Nuun, Tailwind, and Skratch Labs offer convenient powders and tablets for mixing.

Caffeine: The Performance Booster

For runners who are used to it, caffeine can provide a significant performance boost. Studies show that a moderate dose of caffeine, consumed 30-60 minutes before a race, can increase alertness and competitive performance. However, caffeine is also a diuretic, so it should be used cautiously and practiced during training to ensure it doesn't cause stomach issues.

Timing Your Hydration Strategy

It's not just about what you drink, but when you drink it. A well-timed approach ensures optimal absorption and avoids bloating or frequent bathroom stops.

Evening Before: Many experienced runners consume a sodium-rich electrolyte drink the night before the race to preload their body and increase blood plasma volume.
Two to Three Hours Before: The American College of Sports Medicine recommends drinking about 16 to 20 ounces of water or sports drink two to three hours before the race starts. This gives your body time to absorb the fluids and excrete any excess.
45-60 Minutes Before: Some strategies suggest finishing your final pre-race drink around this time, especially a sodium-rich electrolyte beverage, to allow for optimal absorption and prevent the need for a last-minute pit stop.
15 Minutes Before: A final small sip of 6-8 ounces of water or electrolyte drink can provide a final top-off without overwhelming your stomach.

Comparison of Pre-Race Drink Options


Drink Type	Primary Benefit	Key Considerations	Best Timing
Electrolyte Sports Drink	Replenishes electrolytes, provides carbs for energy, and enhances fluid retention.	Can be high in sugar; choose a formula tested during training to avoid stomach upset.	Days before and race morning, 2-3 hours before start.
Plain Water	Essential for basic hydration.	Contains no electrolytes; risks hyponatremia if consumed in large volumes before exercise.	Daily hydration; best for small sips in the final hour before the race.
Caffeine (Coffee/Tea)	Boosts mental alertness and endurance performance.	Diuretic; can cause stomach issues; only use if practiced in training.	30-60 minutes before the race start for peak effects.
Homemade Electrolyte Drink	Customisable ingredients and taste; avoids artificial additives.	Requires planning and testing; sodium concentration is critical.	Can be used throughout the preparation phase and on race day.

What to Avoid Before Your Marathon

Equally important is knowing what to leave out of your race-day nutrition plan.

Alcohol: It's a diuretic that promotes fluid loss and can negatively impact performance, recovery, and coordination for up to 72 hours. Avoid it in the days leading up to the race.
Sugary Sodas: High sugar content can cause a rapid spike and crash in blood sugar, and the carbonation can lead to bloating and gastrointestinal distress during the race.
Excessive Plain Water: Gulping large volumes of plain water, especially right before the start, can increase the risk of hyponatremia. It is a dangerous and preventable condition that can be avoided by incorporating electrolytes.

Creating Your Personalized Hydration Plan

Every runner's sweat rate and electrolyte needs are different. The best hydration strategy is one that has been practiced and refined during training, especially during long runs. Monitoring body weight before and after training runs is a simple method to estimate fluid loss and determine your needs. For every pound of body weight lost during a run, you need to consume approximately 16 to 24 ounces of fluid to replenish losses. A hydration plan should be a dynamic strategy, adjusted for weather conditions and running intensity. A hot, humid day will require a more aggressive approach to fluid and electrolyte intake than a cool day.

Conclusion: Sip Smarter, Run Stronger

Understanding what do marathon runners drink before a race goes beyond simply grabbing a sports drink. It involves a strategic, personalized approach to fluid and electrolyte intake that begins days before the starting gun. By opting for balanced sports drinks or electrolyte mixes, timing your intake carefully, and practicing your hydration strategy during training, you can significantly reduce the risk of dehydration and hyponatremia. The right hydration plan is an essential component of a successful race, ensuring you start strong and finish strong.

For more detailed information on preventing hyponatremia, refer to this resource on marathon hydration advice.

Frequently Asked Questions

No, while water is essential, it's not enough on its own for a marathon. Your body loses crucial electrolytes, especially sodium, through sweat. Drinking excessive plain water without replenishing sodium can lead to hyponatremia.

Most experts recommend drinking 16 to 20 ounces of fluid, like a sports drink, about 2 to 3 hours before the race. Then, a final small top-up of 6-8 ounces is recommended about 15 minutes before the start.

It is generally advised to finish your main pre-race hydration about 45 to 60 minutes before the start. This allows your body to absorb the fluids and gives you time for a final bathroom trip.

If you are a regular coffee drinker, a cup 30-60 minutes before the race can boost alertness and performance. However, because it is a diuretic and can cause stomach upset, it should only be used if you have practiced with it in training.

Alcohol is a diuretic that dehydrates you. It impairs coordination, slows recovery by affecting muscle repair, and can significantly reduce your athletic performance.

Hyponatremia is a potentially dangerous condition where blood sodium levels become too low, often caused by overconsuming plain water during or before a race. You can prevent it by hydrating with an electrolyte-enhanced drink, not just plain water, and avoiding gulping large volumes.

Sports gels are primarily for carbohydrates and energy, while sports drinks address both energy and hydration (electrolytes). Many runners use both, consuming gels with sips of water. The best strategy depends on your individual needs and should be practiced during training.

Natural alternatives include coconut water for its potassium content or homemade electrolyte drinks made with water, a pinch of salt, and fruit juice.