[Research Rundown] Is Caffeine Actually Helpful for Runners?

As a self-proclaimed coffee snob and caffeine addict, I used to start every morning with a cup of coffee (and carbs!) before heading out for my run. I've since switched to plain water or an electrolyte drink, but my curiosity about caffeine and running hasn’t gone away.

Plenty of runners swear by pre-workout, energy drinks, or a strong cup of black coffee before training, and I was curious if it was actually effective or just another running myth.

Caffeine has well-established health benefits: reducing the risk of Alzheimer's,, Parkinson's disease, Huntington's disease, chronic pain, and even depression (One study even found that people who drank more than two cups of caffeinated coffee per day were 24% less exposed to depression than those who did not drink coffee). It also stimulates brain function and improves focus. (https://pmc.ncbi.nlm.nih.gov/articles/PMC8467199/)

As for athletic performance, caffeine supplementation is commonly recommended to boost endurance performance, but most of the evidence supporting its ergogenicity (AKA performance-enhancing benefits) in aerobic exercise comes from studies on cycling, not running.

So I dove into the research, partly for science, partly for my love of coffee.

The Study: How Does Caffeine Affect Endurance Running Performance?

Researchers wanted to better understand how caffeine affects endurance running performance specifically, not just endurance sports in general. Prior to this study, there was only one systematic review about the effect of caffeine on endurance running performance, where the authors concluded that caffeine intake enhanced runners' athlete performance by 1.1%. However, it was done in 2013, so the authors decided, given all of the research that's been conducted since then, it was time for a more current study to see if anything has changed.

To do this, they did a systematic review and meta-analysis, which is a fancy way of saying they:

• Collected all the existing high-quality studies on caffeine and running

• Evaluated which studies were reliable enough to include

• Crunched the numbers across all those studies to see what trends emerged

They ended up including 21 studies published between 1991 and 2022, involving a total of 254 runners (220 men, 19 women and 15 participants with no information about gender). All of the studies compared caffeine to a placebo, using a crossover design (which helps control for individual differences), and looked at two key performance outcomes:

1. Time to exhaustion – how long runners could go before they had to stop

2. Time trial performance – how long it took runners to complete a set distance 

Across these studies, runners consumed caffeine doses ranging from 3 to 9 mg per kilogram of body weight, amounts shown in previous research to be within the effective performance-enhancing range.

The Findings

Caffeine helps you run longer before reaching exhaustion

In this systematic review, seven studies tested the effect of caffeine on running protocols that had participants perform "sub-maximal intensity running until they could no longer maintain the required speed." Overall, the values of time to exhaustion were higher with caffeine than with the placebo group, and the meta-analysis revealed a statistically significant effect of caffeine in this performance variable.

Scientists hypothesize that this is because caffeine promotes the production of two neurotransmitters: beta-endorphins which regulate the body's perception of pain, stress response, and reward pathways, and dopamine, which plays a crucial role in movement, motivation, pleasure, and the brain's reward system. The production of these neurotransmitters can lessen perceived effort and discomfort. The researchers found that caffeine led to an average performance increase of about 17%, but there was a lot of individual variation (±14.65%). Some runners improved much more, while others barely noticed a difference.

Now, time-to-exhaustion tests don’t perfectly mimic real races, but they’re useful for understanding how fatigue works and how caffeine can blunt it. This effect might be especially relevant for ultramarathoners, trail runners, or anyone racing close to their limits.

Caffeine slightly improves performance in time trials

In time trials (running a fixed distance as fast as you can), caffeine led to a very small but statistically significant improvement—just 0.71% faster on average.

That might not sound like much, but over a 10K, that’s around 25–30 seconds saved. For some runners, that’s the difference between a PR and “almost got it.”

It’s worth noting that caffeine seemed to work equally well for both trained and recreational runners, and across both middle- and long-distance events.

Why Does Caffeine Work?

Caffeine works on both your body and brain. It blocks adenosine receptors in your brain, which are responsible for feelings of fatigue and pain. This allows you to:

• Feel less tired during exercise

• Perceive less effort

• Delay muscle fatigue

• Potentially run faster with the same level of discomfort

So basically, caffeine doesn’t magically make your legs stronger—but it makes the run feel easier, which can help you push a little harder or go a little longer.

Takeaways for Runners 

Here’s the bottom line:

✅ Yes, caffeine can help you perform better as a runner, especially if you're doing longer races or pushing into fatigue.

✅ The benefit is bigger for “run till you drop” type efforts (like ultras or brutal long runs), but even in race-style time trials, there’s a small edge to be gained.

⚠️ The effect isn’t huge, and it won’t turn a bad race into a great one—but it can give you that extra push, especially if you use it strategically.

So... Should You Take Caffeine Before Every Run?

Not necessarily. Here’s what to keep in mind:

• Effective doses are typically 3–6 mg of caffeine per kg of body weight, taken 30–60 minutes before running. (That’s about 200–400 mg for most people—a strong cup of coffee or a caffeine gel.)

• More isn’t better. Going above 6–9 mg/kg doesn’t increase the benefit—and may cause jitters or GI issues.

• If you’re caffeine-sensitive, test it in training before race day.

• You don’t need to “quit caffeine” beforehand for it to work—but some runners do taper caffeine before a race to feel the effects more. 

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Ready to train smarter (not just harder)?

If you’re wondering how to structure your training, when to push, when to pull back, or whether things like double runs even make sense for you, we've got resources to help:

✅ Downloadable Training Plans – for every distance, from 5K to marathon

✅ 1:1 Coaching – personalized guidance, support, and feedback from expert coaches

✅ Group Coaching Programs – structured team training for specific race goals

Wherever you are in your running journey, we're here to help you run smarter, build confidence, and enjoy every step!

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Sources:

Grant DD. Yup, Running a Marathon Makes You Dumber. RUN | Powered by Outside. Published April 28, 2025. Accessed June 18, 2025. https://run.outsideonline.com/nutrition-and-health/general-health/yup-running-a-marathon-makes-you-dumber//

Ramos-Cabrer P, Cabrera-Zubizarreta A, Padro D, Matute-González M, Rodríguez-Antigüedad A, Matute C. Reversible reduction in brain myelin content upon marathon running. Nature Metabolism. Published online March 24, 2025. doi:https://doi.org/10.1038/s42255-025-01244-7.

Tarun Sai Lomte. News-Medical. News-Medical. Published March 26, 2025. Accessed June 18, 2025. https://www.news-medical.net/news/20250325/Marathon-running-temporarily-reduces-brain-myelin-levels.aspx

asel). 2024;12(8):226. Published 2024 Aug 20. doi:10.3390/sports12080226.

This article was researched and written by Sophie van Leeuwen, social media and podcast assistant at Running Explained.