July 07, 2023 3 min read

Coffee owes much of its nutritional properties, as well as its unmistakable taste, to caffeine. With an estimated two billion cups of coffee drunk worldwide every day, caffeine is arguably the most widely consumed performance-enhancing drug on the planet.  After it was removed from the World Anti-Doping Agency banned list in 2004, its use has been steadily growing across a wide variety of sports including aquatics, athletics, boxing, judo, football, and weightlifting.

In this post, we will examine the relationship between coffee, caffeine, and sports performance.

What does caffeine actually do to an athlete’s body?

The effects of caffeine on the body vary from person to person and depend on several factors, including the amount taken, individual tolerance, age, weight and general health conditions.

Caffeine is a psychoactive drug, meaning it directly affects the brain. Specifically, caffeine is classed as a stimulant since it increases (or stimulates) the activity of the nervous system and brain. This explains the feelings of wakefulness or alertness that most of us associate with caffeine.

Does caffeine enhance athletic performance?

Yes, although there is a very wide variation in results from almost all trials investigating caffeine.

runner coffee caffeine athletic performance

Caffeine is considered one of the best-tested ergogenic aids (substances, devices, or practices that enhance an individual's energy use, production, or recovery), and is known to help athletes train harder and longer. Caffeine stimulates the brain and contributes to clearer thinking and greater concentration. The most studied and well-known of these effects is caffeine’s ability to temporarily block adenosine, the neurotransmitter associated with sleepiness. 

Studies have shown that caffeine affects athlete’s exercise performance by reducing fatigue, blocking the aforementioned neurotransmitter adenosine, and increasing alertness and precision. More relevant for athletes, it also increases the stimulation of the central nervous system, making physical exertion feel like it involves less pain and effort. 

What is the right amount of caffeine that an athlete should consume?

The amount of caffeine recommended for athletes should be a little higher than that recommended for ordinary people, because this substance improves physical performance and concentration and reduces muscle fatigue. In general, those who practice sports on a daily or almost daily basis should take 3 to 5 mg per kg of body weight per day, adjusted according to the intensity of physical activity. Be careful, however, not to overdo it, because it may bring up the risk of an increase in blood pressure and an acceleration of the heart rate. 

Many athletes consume caffeine in the form of a food supplement (chewing gum, capsules or energy drinks). Such supplements are among the few to have a real ergogenic effect. In fact, they help improve performance in all disciplines, from those involving short but intense efforts to endurance activities up to team sports. 

Which are the best moments of the day to take caffeine for an athlete?

woman drinking coffee in the morning

The most suitable moments are those preceding morning and early afternoon training sessions. If taken before a sporting activity, this substance stimulates the central nervous system and muscles and promotes a delayed perception of fatigue. These effects are particularly marked in disciplines that require prolonged efforts, such as cycling. 

To combat fatigue, it is sometimes possible to consume caffeine, in quantities not exceeding 40 mg, even during training. In doing so, it also facilitates the absorption of sugars in the intestine. If taken after physical activity together with foods rich in carbohydrates, this substance helps restore muscle glycogen doses. However, due to its diuretic effect, those who sweat a lot during training should avoid its consumption.

Are there positive effects of caffeine for non-athletes?


In addition to its ability to reduce the feeling of fatigue and increase attention, caffeine increases the basal metabolic rate, helping to burn fat faster. Furthermore, it has benefits on memory, in particular on short-term memory, and on the digestive system. According to some studies, moderate consumption of this substance has positive effects on mood and according to other scientific research it reduces inflammation. 

Caffeine and common sense

Because each person responds differently to caffeine, don't assume you'll automatically perform better athletically with a caffeine-boost. You might just end up nauseated, coping with a "coffee stomach," or suffering from caffeine jitters at a time when you're already nervous and anxious. Clearly, you have to learn through trial and error the amount of caffeine that works best for your body - if any at all.

And be forewarned: while a morning cup of coffee can assist with a desirable bowel movement, a pre-competition cup might lead to transit troubles! Experiment during training to determine if a caffeinated beverage or plain water is your best bet.