Caffeine & Fitness


Caffeine is the most commonly used energy booster. A Lot of people usually rely on caffeinated beverages to get their energy going, but athletes on the other hand, have long depended on caffeine to enhance their performance and focus during training and competition. Today, we’ll dive deep into what caffeine is, how it can improve performance, and if there’s a specific form of caffeine that will work best for your goals.

What Is Caffeine And How Does It Work?

Many people drink caffeine for their morning and mid-day pick-me-up, but athletes have actually been consuming caffeine to enhance performance for decades (if not even longer). In fact, back in 1939 (6), caffeine was pushed to be banned in all sports. Pretty much everyone has experienced caffeine one way or another, so it’s worth talking about what it actually is and what it does.

Caffeine is found in various plants. Commonly used in coffee beans; various teas and even cacao, in which all are natural caffeine content. Caffeine is labeled as a stimulant, which means that it “energizes” us in comparison to substances like alcohol, which is classified as a, “depressant.” How can caffeine energize us you might ask?

There are a handful of theories but the one that’s easier to understand is that caffeine blocks adenosine receptors in the brain. Once adenosine is engaged with receptors in the brain(6,7), it increases drowsiness and relaxation. The fact that caffeine reacts to this binding location, causes the exact opposite – which is alertness and energy. This blockage of adenosine can also contribute to hormones throughout the body. There’s also an increase in blood levels of epinephrine when people consume caffeine. Epinephrine is also known as, “adrenaline,” and is responsible for our heart rate to increase, causes our muscles to produce more force, and even helps with our metabolism.

Studies show that caffeine can also improve pain tolerance (6). There are many pain medications that contain caffeine to help alleviate pain symptoms. This is one of the reasons why athletes and bodybuilders often use caffeine; the burn isn’t as painful when you have caffeine in your system.

Another interesting fact about caffeine is that it can increase the performance of the heart through a unique interaction with the muscle cells that are in the heart. Cardiac muscle fibers share similar attributes to skeletal muscle. However, we have more functional control over our skeletal muscle which creates a wide range of force within our skeletal muscles. All of our muscle fibers adhere to a few laws, one is known as the Length-Tension relationship. The concept behind length Tension relationship is that a muscle fiber will promote x-amount of active force at a specific length.

When our heart is filled up with more blood, the muscle fibers of the heart will expand wider than it does at rest. This will result in the hearts muscle fibers to increase force while it contracts. This increased force pumps more blood which causes an increase of oxygen to be delivered to the muscles. When it comes to force production, cardiac muscle fibers become dependent on calcium concentration (2). A a small amount of calcium in these muscle fibers can reduce contraction, which will reduce force and overall cardiac output . Caffeine on the other hand, can actually help promote calcium concentration and sensitivity in cardiac muscle fibers .This helps the heart produce high levels of force, even while in an exhaustive state (1). Essentially, caffeine helps our heart pump more blood.

Performance & Endurance Effects

Endurance training is one of the most common sports/hobbies in which caffeine is consumed. Studies consistently conclude that there is a clear benefit of consuming caffeine before training or competition. However, positive effects depend on variables such as dosage, nutrition status, and even timing (3). Caffeine can increase endurance performance by enhancing alertness, and modifying circulating hormone levels.

Like I spoke about earlier, the most essential action of caffeine when it comes to endurance and performance is its ability to compete for adenosine receptors. The fact that adenosine contributes to drowsiness and fatigue, this can hinder muscle performance and even produce central nervous system fatigue, which makes it difficult to activate our muscles. Eventually adenosine will lead to an increased perception of both exertion and pain, and at some point of time you will want to quit training. This is the reason why caffeine has consistently proven to enhance performance in tests that include either distance or time to exhaustion (3). Even though these tests aren’t the most scientifically-sound, they help gather more data on how caffeine can increase performance.

It’s known that caffeine consumption can enhance metabolic rate due to its effects on various hormones (6). Nevertheless, caffeine can also increase fatty acid oxidation, which improves our ability to utilize fat as fuel (3). Since fat is the main fuel source in long distance, low-to-moderate intensity training, enhancing fat oxidation can help increase performance during these exercises.

Effects On Strength

Like the majority of exercise or nutrition-related research, most of the studies utilizing caffeine provide an endurance or cardio protocol, rather than including strength training. As of recently, research has examined the effects of caffeine on strength and power performance. Multiple studies have proved that caffeine can increase strength and power performance, but interestingly enough, caffeine may be more effective for enhancing upper body strength vs lower body strength (7).

How can caffeine improve strength? Alertness and overall arousal play a big role. For example, if you’re fatigued or feeling down before taking caffeine, you’re going to experience a boost in your strength. However, caffeine mainly builds strength by increasing muscle activation. Since caffeine blocks the activation of adenosine, our muscles are able to perform heavy or powerful lifting (7). Caffeine affects training performance from both a psychological (energy/focus) and physiological standpoint (muscle recruitment and fatigability).

Why does research not report a consistent increase in lower body strength from caffeine? Keep in mind that studies are limited by the scientific method, so they won’t always be congruent to real world training. While testing for strength on the lower body, movements are normally more complex and require a higher level of training experience and skill compared to upper body movements. Since most research uses untrained or moderately trained subjects, it’s difficult to compare upper and lower body strength tests, hence lower body strength tests may not be as reliable.

Gender differences are also relevant to the limitations of science and caffeine response. There’s no reason to imply that there’d be significantly different effects between men and women consuming caffeine, but unfortunately, there’s not much data on the effects of caffeine with female participants (7).

There’s also not many statistics on populations other than young adults. It remains undocumented if older adults will have a different response to caffeine consumption. I have a hunch that caffeine could be even more effective for older adults, especially when it comes to improving strength and fatigability.

Dosage & Safety

Research has been pretty consistent in documenting that the most effective dosage for caffeine consumption is somewhere between 3mg/kg of bodyweight and 6mg/kg of bodyweight (3,7). For a 200lb person, that would equal to a range of 272-545mg. It’s important to take note that this doesn’t mean you have to have this much caffeine. Some people could be more sensitive to caffeine and don’t need that much to get the job done. Personally I used to be the 2-3 scoops of pre-workout kind of guy because I needed 4-500mg of caffeine to get a boost for my workouts.. Now I stick with only 150mg of caffeine and get plenty amped with that. These are anecdotes, but do understand that the 3-6mg/kg is a recommendation, not a rule of thumb. Some individuals might feel a boost off of a single cup of coffee (roughly 100mg of caffeine), but the noticeable objective performance benefits begin around 3mg/kg of bodyweight.

What’s the best way to time your caffeine consumption around your workout? I’d recommend taking caffeine between 30-60 minutes before exercise. People normally see optimal blood levels around 60-minutes after consumption (6) which is why I recommend this timing. It’s best to avoid taking caffeine after your workout because caffeine can actually impair insulin sensitivity (12) and cause vasoconstriction (6). Both factors are definitely unwanted when trying to recover from a workout.

As far as safety, caffeine really doesn’t have any long-term health concerns or create any complications (6). However, this is referring to healthy people with no underlying conditions. If you have any type of cardiovascular disease or metabolic disease, you have to check with your physician before taking caffeine. In addition, caffeine can potentially worsen symptoms of anxiety and nervousness in some individuals (11), so if you’re prone to having anxiety, caffeine would not be the best bet for you. Lastly, it’s best to avoid taking caffeine close to bedtime as it can impair quality of sleep (11). Sleep is much more important for performance improvements and recovery than any supplement could ever be. So be sure to not mess with your sleep schedule!

Tolerance is another issue to look after when it comes to caffeine. Over time, we eventually start to adapt to our daily caffeine dose and no longer get the same energy out of that dose. This is why many people end up increasing their dose – hence why I was taking 2-3 scoops of pre-workout years ago. However, taking as little as a 7-day caffeine break can help bring your sensitivity back to where it was so you don’t have to buy a new container of pre-workout every 2-weeks. How fast does our tolerance build to caffeine? Unfortunately we adapt in as little as 15-days of consistent use (9).

What’s the best way to reduce the development of tolerance? The best way is to simply make sure that you’re not consuming caffeine every day [insert screaming emoji here]. I know this sounds almost impossible to do, but it will help keep your sensitivity in check. If that’s just not possible for you, aim for planning a week out of every month or two where you avoid caffeine for the entire week. Again, this could definitely be an awful week for you, but it will surely keep tolerance at bay!

What’s The Best Form Of Coffee?

Everyone knows that we can get caffeine from different sources; coffee, pills, chocolate, etc. But the question remains, is there a best form for exercise? Recent studies suggested that caffeine sourced from coffee might not be as efficient as the anhydrous (pill) form of caffeine. There was theory that some of the other bioactive components of coffee could interfere with caffeine’s effects (4). However, later studies were not able to duplicate those results (8), so it’s probably not as big of a deal as we initially thought.

Another type of caffeine that’s commonly used is tea. especially green tea. However, many have discussed if green tea is actually an effective source of caffeine since it also has the amino acid, L-theanine, which enhances relaxation. There’s not a ton of information regarding this combination in the realm of performance studies, but it has been documented that L-theanine can counteract some of the negative side effects from caffeine consumption, such as anxiety or jitters (10). Therefore, if you’re considering giving up caffeine use due to the side effects, try giving green tea a shot for a potentially smoother rush.

Overall, there’s not a specific form of caffeine that’s going to have magical effects in comparison to other forms. The best advice that I can give is for you to stick to whatever’s most convenient for you and your goals, whether that be a preworkout drink, caffeine pills, or a mug of coffee.


All-in-all, caffeine is one of the most effective supplements for athletes looking to enhance their performance. The majority of research on caffeine examines the acute effects of caffeine consumption, but if you reap these benefits throughout a long-term training routine, you’re going to see improved muscle development . Try your best to follow a strategy that promotes sustained sensitivity to caffeine – whether you make sure that you don’t take it every day or you take a week off every month or two. Long term use of caffeine is perfectly safe, just double check with your physician if you have any pre-existing conditions. Lastly, any form of caffeine is probably going to provide a boost both in and out of the gym, so use whatever form works best for you!










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