Coffee Before Running: What Science Says About It

Are you curious about whether you should drink coffee before running? What about caffeinated supplements during your race? Some runners view caffeine as bad, due to concerns about jitters or urgent bathroom stops. Others must have their caffeine before any run, training or race. So is caffeine bad or good for runners? This article will delve into the science of caffeine supplementation and how to know if it is right for you – and if so, how to use coffee before running correctly for optimal outcomes. 

So, will will caffeine help before a run? Keep reading to find out.

Is caffeine bad or good for runners?

Overall, coffee before running (or any type of caffeine) generally positively affects endurance performance. A 2022 review in Nutrients pooled data from 21 studies and found that caffeine improved both time to exhaustion (endurance performance) and time trials (how fast you can run a certain distance). The study found a 16.97% (+/-14.65%) improvement in time to exhaustion and a 0.71% (+/-0.83%) improvement in time trial performance. These results were the same for both highly trained and recreational runners. Other reviews report an average of 2-4% average improvement in performance, with a range of -3.0 to +15.9%. 

Caffeine improves running performance by crossing the blood-brain barrier and inhibiting the adenosine receptors in the brain. When caffeine blocks adenosine uptake in the brain, you experience less fatigue and a lower perception of effort during exercise, allowing you to push harder or run longer. Caffeine also mobilizes calcium ions in the muscles and aids in the oxidation of carbohydrates, both of which further enhance performance. 

The response to caffeine is highly individual – because it’s genetic. A 2018 randomized controlled trial in Medicine and Science in Sports and Exercise demonstrated that CYP1A2 genotype impacted an athlete’s response to caffeine. AA genotypes improved time trial endurance performance, AC saw no difference, and CC actually performed worse at higher doses. (Meanwhile, gender does not make an observable impact on caffeine response.) 

 While you likely won’t learn your genotype, you can observe your individual response. Do you perform best after drinking some coffee, or are you sensitive to the side effects of caffeine? This reason is why you will want to test caffeine supplementation in training – to understand your individual response. 

Best sources of caffeine for runners

If you are searching for a hit of caffeine before running, your primary options are coffee, tea, energy drinks, and sports nutrition supplements. Which one you choose will depend on your desired dosage – and your taste preference.

Coffee

Many runners ritually drink coffee before running. Eight ounces of brewed coffee typically contains an average of 95 mg of caffeine, while espresso offers approximately 63 mg per shot. (More than likely, your mug contains more than 8 oz.) The bean type and the roasting style will impact the exact caffeine concentration.  

Many runners favor coffee for its ease. You can make coffee at home or drink a prepared cold brew before any training run. The higher caffeine content of coffee allows you to ingest the recommended dosage with relative ease (more on that below). For example, if you are a 143-lb runner (65-kg), you can reach your recommended dosage of 130-260 mg of caffeine with a 12-oz mug of brewed coffee. 

The acidity of coffee is a concern before a run. You can minimize the effects of the acidity by ensuring you eat some bland carbohydrates before your run (such as these pre-run snacks). 

Tea

Tea is a viable option if you want caffeine before running but do not like coffee or want a smaller dose. While some teas are caffeine-free, black tea and matcha tea do provide caffeine in smaller doses than coffee. Matcha tea has approximately 19-44 mg of caffeine per gram, so the exact caffeine content depends upon how many scoops you use. Black tea has approximately half of the caffeine content of coffee, with 40-45 mg per 8 oz serving. 

Energy drinks

Energy drinks contain caffeine and other ingredients, such as B-vitamins, amino acids, and other ergogenic supplements. These products may contain ingredients not approved by the FDA and could have adverse effects for some individuals (as outlined in this 2023 review in Nutrients). Energy drinks often contain higher doses of caffeine than coffee or tea. For example, the popular energy drink Celsius contains 200-300 mg of caffeine per serving. For that reason, energy drinks are not recommended for endurance athletes. 

Caffeine supplements

Many popular supplements for runners – such as gels and sports drinks – contain caffeine. While coffee and tea can provide caffeine before a run, these products enable you to ingest caffeine while running. Typically, gels and sports drinks contain 25-50 mg of caffeine per serving. However, some gels do contain up to 100 mg of caffeine. 

Pre-workout is another common caffeine-containing supplement. However, pre-workouts are not heavily regulated – so you may not get the exact amount of caffeine (or other ingredients) listed. If you do take a pre-workout, pick one that is third-party tested. (This article discusses pre-workout for runners in greater detail.) 

Timing and dosage recommendations

According to the International Society of Sports Nutrition, the optimal dosage for performance enhancements is 3 to 6 mg of caffeine per kilogram of body weight. Some athletes may respond to as low as 2 mg of caffeine. Once you reach ~9 mg of caffeine, you are very likely to experience adverse effects (see more below). 

For a sample 65-kg runner (143-lbs), the recommended dosage is 195 to 390 mg of caffeine over the course of a race morning. However, if you are cautious about side effects, you may want to try 2 mg/kg (130 mg for this sample athlete). This amount includes caffeine consumption before and during exercise. If you have a 12-oz brewed coffee and two caffeinated gels during a marathon, then your caffeine intake is within the recommended range. Generally, it is recommended not to exceed more than 400 mg per day and to avoid large singular doses. 

Caffeine takes approximately 60 minutes to peak in your system. Typically, it is recommended to time your caffeine ingestion about 45-60 minutes before your race starts, especially if competing in a shorter event. You want to time any caffeinated gels for approximately 60 minutes before you want to feel the boost. For example, if you want to experience caffeine’s erogenic boost over the final 10K of a marathon, aim to take a caffeinated gel 5-7 miles before miles 21-22. 

Potential risks and side effects

Caffeine can produce adverse effects, particularly in high doses and in sensitive individuals. The side effects of caffeine include gastrointestinal upset, tachycardia (high heart rate), heart palpitations, anxiety, and headaches. Some research theorizes that caffeine intake could be one of the many triggers leading to muscle cramping. 

Your caffeine metabolism rate may spur additional side effects. While caffeine typically leaves your system within 6-8 hours, some individuals may notice that taking caffeine even in the mid-day disrupts their sleep. 

Bonus: How to think about coffee before a marathon

Since the research indicates that caffeine has a moderate to large effect on time to exhaustion, it makes sense to consider coffee before a marathon (or ultra-marathon). The ability to manage late-race fatigue is essential for running your best marathon. If you tolerate caffeine well, you could use coffee before a marathon and caffeine during the race to help you push through those final tough miles. 

Always test any nutritional strategies – including caffeine usage – before a race. Consider what you plan to take on race day in any pre-race trials. If you are traveling for a marathon, you can try a cold brew coffee, which stores easily in the hotel fridge the night before. 

A sample plan for taking coffee before a marathon:

• One to two hours before the race: pre-race breakfast, 12-16 oz of sport drink, and 8-16 oz coffee or tea (depending on dose)
• During the marathon: caffeinated gels (25-50 mg each) at mile 6 and mile 15

Related: Should You Do a Caffeine Fast Before a Marathon?

Running and coffee: A match made in heaven?

Coffee before running can improve your endurance and reduce your perception of effort. However, it is individual – if you notice a response and have minimal side effects, then caffeine before a run can benefit you. If you do not respond well to caffeine, then forgo it before running, especially races. 

It is important to remember that while coffee does not dehydrate you, you will still want to consume fluid with electrolytes before a run or race. While caffeine reduces fatigue, it does not actually provide the metabolic substrates for energy production – meaning that you still need to consume carbohydrates before and during your runs. 

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