Caffeine and Running Performance: What the Science Says
As runners, we're always looking for that extra edge—whether it's shaving seconds off our personal record or simply feeling stronger during those long training runs. One of the most accessible and well-researched performance enhancers might already be sitting in your kitchen: caffeine.
At the 2025 Mountain Land Running Summit in Park City, Utah, Dr. John Dopp, a pharmacologist at the University of Wisconsin-Madison, presented compelling evidence on caffeine's role in athletic performance. Here's what runners need to know about this powerful, legal ergogenic aid.
The Science Behind the Boost
Caffeine works by blocking adenosine receptors in the brain, which reduces perceived effort and fatigue during exercise. This mechanism enhances fuel efficiency and oxygen delivery to muscles, allowing you to run harder for longer. Recent research shows the effects are significant: a 2023 meta-analysis found that caffeine increased time to exhaustion by approximately 16.97% compared to placebo. Even in time trials, where every second counts, caffeine reduced completion times by 0.71%—a meaningful advantage in competitive racing.
Finding Your Optimal Dose
The sweet spot for performance enhancement is 3 to 6 mg of caffeine per kilogram of body weight, taken about 60 minutes before exercise. For a 150-pound (68 kg) runner, that translates to roughly 200-400 mg of caffeine—equivalent to two to three shots of espresso or two to four cups of coffee.
Why 60 minutes? That's when caffeine reaches peak blood levels, and its ergogenic effects can last 3 to 5 hours. Interestingly, research shows no additional benefit from higher doses, so more isn't better when it comes to caffeine and performance.
Important Considerations
While caffeine can offer a 2-7% improvement in endurance and time to fatigue, there are some caveats. Habitual caffeine users may develop partial tolerance to its performance benefits, though this can be reversed with 20 to 28 days of abstinence before competition. Additionally, caffeine taken for evening events can significantly impair sleep quality—increasing wake time and reducing sleep efficiency.
For runners dealing with sleep deprivation, caffeine can help mitigate performance impairments, potentially improving time trial performance by up to 7.7% in sleep-deprived states. However, if you're well-rested, the additional sleep-related benefit isn't present.
Side Effects to Watch For
While generally safe, caffeine can cause jitteriness, increased heart rate, anxiety, and gastrointestinal issues—particularly problematic during races. Its five-hour half-life means evening consumption can disrupt sleep, which is crucial for recovery and adaptation to training.
Putting It Into Practice
The key to using caffeine effectively is individualization. Test different doses and timing during training runs, not on race day. Monitor how it affects both your performance and your sleep. Consider using lower doses for evening competitions to minimize sleep disruption.
Ready to Optimize Your Performance?
Understanding how to use caffeine strategically is just one piece of becoming a stronger, healthier runner. At Oregon Running Clinic, our physical therapists specialize in helping runners maximize their performance while minimizing injury risk. Whether you're training for your first 5K or chasing a Boston qualifier, we can help you develop a comprehensive plan tailored to your individual needs.
Schedule a consultation with Oregon Running Clinic today to discuss your training goals, address any running-related concerns, and learn evidence-based strategies to help you run faster, longer, and healthier.