Two-time Olympian and 2018 Boston Marathon champion Des Linden drinks three to four cups of coffee each day. “I’m a huge coffee fan,” Linden tells Runner’s World, better heart health, Linden x Two. “I have two cups first thing in the morning, and it’s beneficial in getting all systems—mind and body—up and running before I head out the door for my first run,” she adds.
Many of us—elite and non-elite—use caffeine to our benefit, as research has shown that in addition to perking you up, it can also make you faster, help you focus during your workouts, boost muscle recovery afterward, and improve overall circulation.
But like any other performance food or drink, education is key to achieving maximum benefits, so we tapped experts and the latest research to tell you everything you need to know about your favorite energizer.
The Benefits of Caffeine for Performance
Unless you have a sensitivity, caffeine can be highly beneficial for most people, according to Todd Buckingham, Ph.D., exercise physiologist at Mary Free Bed Sports Rehabilitation Performance Lab.
“[It’s] shown to increase mental alertness and concentration and improve athletic performance by increasing time to exhaustion, so I often do recommend caffeine to my runner clients, as long as they tolerate it well,” says Angie Asche, M.S., R.D., C.S.S.D., sports dietitian and owner of Eleat Sports Nutrition, agrees.
In fact, studies dating back to the early ’90s found that taking in around 150 to 200 milligrams (mg) of caffeine from coffee one hour before exercise improved 1,500 meter performance in well-trained runners. More recently, another study reported a 24-second or 1.8 percent improvement in an 8K run time with well-trained male runners when ingesting 3 mg of caffeine per kilogram of body weight one hour before racing.
The overall favorable results of caffeine for running performance have caused many organizations to advocate for its use during sport: The Academy of Nutrition and Dietetics states that caffeine reduces perception of fatigue among athletes and allows exercise to be sustained at optimal intensity for longer periods of time; the International Society of Sports Nutrition suggests that ultramarathoners ingest caffeine in the latter stages of endurance exercise to maintain energy levels; and the European Food Safety Authority says single doses of caffeine up to 200 mg from all sources are perfectly safe when consumed less than two hours before intense physical exercise.
What’s more, a 2021 position statement published by the International Society of Sports Nutrition, states the following:
- Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions.
- Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use.
- Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg per kg of body mass.
- Caffeine appears to improve physical performance in both trained and untrained individuals.
- The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine.
All in all, caffeine consumption seems to have positive effects among most people. That said, not everyone needs caffeine or responds well to it. Buckingham notes that caffeine may agitate some people, and that if you’re not already a caffeine user, starting it now may make you feel nervous or jittery.
“Prior to a race, your body is already in a stressed state so your epinephrine—or adrenaline—level is already high,” he says. “Consuming caffeine on top of that increases the severity of the stressed state, could overstimulate you, and could cause physical exhaustion.” In these cases, it’s best to avoid caffeine altogether or opt for options with less caffeine such as tea.
How Much Caffeine You Should Consume
Typically, the recommendation is to take in 3 to 6 mg of caffeine per kilogram of body weight about 60 minutes before exercising, according to Lizzie Kasparek, M.S., R.D., C.S.S.D., a sports dietitian with the Sanford Sports Science Institute. For a 140-pound person, that’s at least 190 mg per day. For a 180-pound person, that’s 245 mg per day.
To put that into perspective, a cup of home-brewed coffee has, on average, about 100 mg of caffeine. While it’s generally safe to consume up to 400 mg of caffeine per day, Asche says that the amount of caffeine a person should take in depends on the person, their health status, and if they are already consuming caffeine regularly.
“If someone is experiencing negative side effects—such as anxiety and jitters, rapid heart rate, digestive issues, or decreased sleep quality—it would be beneficial for them to evaluate how much they’re taking in and what time they’re taking in that caffeine,” Asche says.
In addition, there has been some emerging research hoping to identify genetic variations in how different people handle caffeine. There are even companies, like Inside Tracker, that will test your DNA to see how quickly you metabolize caffeine.
The Best Sources of Caffeine
There are many natural sources of caffeine, as well as sports nutrition products with added caffeine. Finding the source that is right for you might take some trial and error. Here is a list of common caffeine sources:
Kasparek usually recommends coffee and tea over energy drinks and preworkout beverages because they also contain natural antioxidants and are relatively inexpensive for a prerun beverage. As a matter of fact, some runners like coffee because it helps with bowel movements before a race, and tea has been linked to better heart health.
Race-Day Caffeine Strategies
Experts agree that there are two things to consider when consuming caffeine before a race: timing and the source.
“Prior to exercise, caffeine takes about 10 minutes to enter the bloodstream and typically peaks after 45 to 75 minutes post-ingestion,” says Buckingham.
Asche adds that her clients prefer coffee 45 to 60 minutes before a race, followed by gels or gummies. “It’s so important for runners to take the time to test these different sources out during training runs to really pinpoint what they tolerate best and what they prefer most when it comes to race day,” says Asche.
As for Linden, she sticks with two cups of coffee on the long bus rides to her races. During the marathon she adds in PowerBar PowerGel Hydro with [50 mg] caffeine around the 25K and 30K mark since “it’s that difficult part in the race and . . . caffeine keeps the mind engaged and aware that there is still fuel in the body to be utilized.”
After a race, Linden has a coffee or espresso, although she acknowledges that this strategy might not work for everyone.
“I believe it’s important to celebrate completing a race no matter what the results are, and the caffeine keeps me from bailing on my friends because I’m too tired,” she says.