You’ll find caffeine everywhere on the endurance circuit, popping up in a slew of products—powders, gels, drink, chews, gums, and even sprays. Evidence of its potential as a performance enhancer has been around for years, but scientists and athletes alike are still unpacking the nuances—and the legality—of its application.
Caffeine stimulates the central nervous system, says Todd Astorino, a professor of kinesiology at California State University, San Marcos. It blocks the adenosine receptors (responsible for fatigue), which, in turn, makes you feel less tired. “There is also some evidence that caffeine reduces feelings of muscle pain and perceived exertion, especially during endurance-based exercise,” Astorino says. Other reports tout perks such as increased activation of muscle fibers, leading you to feel faster and stronger, and enhanced mood, which makes long-term repetitive efforts less daunting.
We’ve covered caffeine piecemeal—which products we like the most, how elites get their fix, its effect on memory, what happens when you go without—but we’ve never given a top-to-bottom rundown on how to best work caffeine into your race-day plan. Here’s what to know.
Back Off Your Daily Cup o’ Joe
If you’re already a regular caffeine user, you’ll need to decrease your intake before seeing race-day benefits. Recent research found that athletes who consume a small amount of caffeine on normal days (defined as the equivalent of less than a cup of coffee daily) feel the performance-enhancing effects on race day more than those who consume anything greater than the equivalent of two cups of coffee. Repeated exposure in foods, drinks, and supplements leads to a reduction in sensitivity to the effects of caffeine through a process called habituation, says study co-author Brendan Egan. Just like you taper your weekly mileage, you should taper your caffeine intake during the four days leading up to competition, Egan says. This helps you avoid withdrawal symptoms and ensures you won’t need a large dose of the stuff on race day.
Pick the Right Source
“Research has shown that out of all the different ways to get caffeine into your system, its anhydrous form (simply pure caffeine) is most effective in enhancing performance,” says Philip J. Prins, an exercise physiologist at Grove City College. It’s easy to overdo it on the powder, though, and it’s unregulated by the FDA, so other methods are typically safer while still giving you a boost. Prins’ research found that when runners drank a Red Bull energy drink containing 500 milliliters of caffeine 60 minutes before exercise, they ran a 5K 30 seconds faster, about a 2 percent improvement when compared to placebo. But Prins cautions that if your caffeine comes from a too-sugary drink or gel, it may blunt the caffeine’s impact.
Experiment with Dosage
Most research focuses on doses of one to three milligrams per pound. “Most products for supporting performance are delivered in doses that are multiples of 50 or 100 milligrams, so an athlete needs to keep this framework in mind when experimenting,” Egan says. He suggests starting out on the lower end of the scale and gradually testing greater amounts in 50 milligrams increments until you find the dose that works best for you, since tolerance can be very individualized. If you’re planning to use caffeine for a big event, do these test runs well before that day.
Time It Right
“Taken orally, caffeine typically has its peak impact between 30 and 75 minutes after ingestion,” Prins says. Most of the studies looking at its affect on performance administer the substance one hour before activity, so start there with your most classic products. One exception—caffeinated chewing gum, which can result in a buzz in as few as 15 minutes, Egan says, because it’s rapidly absorbed into the bloodstream through cells that line the mouth.