Caffeine is without a doubt the most widely used psychoactive compound on the planet.
Billions of people use caffeine every day to wake themselves up in the morning, boost their mental acuity in the afternoon, or increase their exercise performance before training and competitions.
But are those the only benefits of caffeine? And does it have any side effects?
What is Caffeine?
In short, caffeine is a compound found in plants that acts as a stimulant.
With this in mind, most people obtain caffeine on a daily basis in coffee or tea. The two plants that produce coffee beans are “Coffea arabica” and “Coffea canephora”, while “Camellia sinensis” is the plant that produces tea leaves.
As many of you would be aware, caffeine can also be found in supplement form, where it is consumed as a powder.
How Does Caffeine Work?
Most of us know that caffeine has some impact on mental wellbeing and cognitive performance -- but what many don't know is how it works.
After you consume caffeine (whether it be in tea, coffee, or supplement form), it quickly enters your gut and digestive tract, before being rapidly absorbed into your bloodstream. From here, it is transported to your liver, before moving throughout your body in several different forms.
After passing through the liver, caffeine can have an effect on a number of your organs -- but where it has the biggest impact is in your brain.
Caffeine moves into the brain and starts attaching itself to certain receptors called “adenosine receptors”.
Adenosine is a neurotransmitter that essentially acts to relax the brain, making you feel tired. Under normal circumstances, your adenosine levels slowly accumulate throughout the day, making you feel tired, thus facilitating your transition into sleep.
However, when caffeine blocks these receptors, it stops adenosine from affecting your brain, increasing sensations of alertness.
Moreover, once in the brain, caffeine also increases the levels of three key compounds that act in your brain and body, being adrenaline, dopamine, and norepinephrine. This further stimulates your brain, leading to increases in mental acuity, alertness, and focus.
I should also note that these effects occur rapidly after consumption.
In fact, caffeine will be in your bloodstream within about 20 minutes, and acting on the brain in full force within 60 -- which explains why your morning coffee is so good, so quickly.
Caffeine Benefits
We know that caffeine acts on the brain in a very potent manner -- and as a result, it can exert a number of different effects on your body.
1. Increased Mental Function
It is well established that doses of caffeine as low as 50mg can increase mental alertness, leading to improvements in attention, reaction time, problem solving capability, short term memory, and judgement [1].
Interestingly, these effects appear to be more pronounced in individuals who don't regularly drink caffeine, or in people who are sleep deprived.
All of which suggests that caffeine can make an extremely potent stimulus if you are in need of a mental boost.
2. Improved Exercise Performance
In conjunction with its potent effects on cognitive performance, there is a huge body of research clearly demonstrating that caffeine can have some seriously powerful effects on physical performance too.
A recent review dove in and evaluated the findings of a whopping 21 meta-analyses (a study that combines the results of multiple studies) on caffeine and various measures of physical performance.
And what did they conclude?
That caffeine can cause significant improvements in strength, endurance, and power [2].
Now if you are training to get as big and strong as humanly possible, this is important because it means taking caffeine can increase the amount of reps you can perform, or the amount of weight you can lift -- which over time, will lead to substantial improvements in strength and size.
So, if you want to get jacked, caffeine could play a role.
3. Promotes Fat Loss
One of the more interesting effects of caffeine are related to its potential impact on fat loss -- which is why it appears in practically every over the counter fat burner on the planet.
Because caffeine is a stimulant, it has the capacity to increase metabolic rate (i.e. the amount of energy you burn to maintain your normal physiological processes). Within this,. It also helps mobilise fat for energy.
In doing so, it can ultimately make it easier to lose fat [3].
Now, the caveat here is that caffeine will not do it all for you. Fat loss is the result of maintaining a sustained energy deficit over a prolonged period of time -- however, it does appear that caffeine can make creating this deficit easier.
4. Prevents Parkinson's Disease and Dementia
Our last benefit sits slightly outside the realm of exercise and training, but that does not make it any less impressive.
Two of the most common issues to plague modern society is Alzheimer's disease and dementia. These issues result in notable age-related declines in cognitive function, leading to a loss of independence, and at times, an early death.
However, there is evidence to suggest that those individuals who drink between 3 and 5 cups of coffee per day during their middle years will reduce their risk of Alzeimers and dementia by approximately 65% in their older years [4].
While there could be a number of reasons for this finding, it is believed that caffeine actually suppresses the production of a certain compound called “amyloid beta” -- which is believed to increase brain inflammation and contribute to the development of Alzheimer's disease.
Caffeine Dosing
Now for the big question -- how much should you take?
Well, most government health authorities across the globe agree that a daily intake of around 400mg is completely safe -- which generally equates to between 2 and 4 cups of coffee per day (depending on the size of the cup, of course).
However, the recommendations for exercise performance are slightly different.
In this scenario, guidelines suggest that you should take somewhere between 3 and 9mg of caffeine per kg of body weight approximately 60 minutes before you are set to commence training [5].
For example, an 80kg individual would take between 240 and 720mg of caffeine to optimise performance.
Now, the thing to note here is that the upper limit of this recommendation sits higher than what many government authorities would consider safe. As a result, opting for a dosage of somewhere between 200 and 400mg is going to be safe and effective for most individuals.
With this in mind, if you are after a pre workout supplement that contains an effective dose of caffeine, it should sit within this range.
Side Effects
As most of you would be aware, caffeine is very well-tolerated when taken in amounts that align with the recommended guidelines. However, taking too much can result in some rather nasty side effects, including [6]:
- Jitteriness and restlessness
- Feelings of anxiety and nervousness
- Becoming dizzy and losing balance
- Diarrhea
- Nausea and vomiting
- The onset of muscle spasms
While most of the side effects do only occur in higher doses, we would recommend talking to a medical professional before supplementing with anything greater than 200mg -- just to be on the safe side.
Final Remarks
Caffeine is one of the most effective performance boosting supplements on the planet. With the capacity to improve mental acuity, boost strength, power, and endurance, enhance fat loss, and stave off dementia, it really can do it all.
Just make sure you stick within the recommended dosages to optimise the results.
References
- McLellan, Tom M., John A. Caldwell, and Harris R. Lieberman. "A review of caffeine’s effects on cognitive, physical and occupational performance." Neuroscience & Biobehavioral Reviews 71 (2016): 294-312.
- Grgic, Jozo, et al. "Wake up and smell the coffee: caffeine supplementation and exercise performance—an umbrella review of 21 published meta-analyses." British journal of sports medicine 54.11 (2020): 681-688.
- Tabrizi, Reza, et al. "The effects of caffeine intake on weight loss: a systematic review and dos-response meta-analysis of randomized controlled trials." Critical reviews in food science and nutrition 59.16 (2019): 2688-2696.
- Eskelinen, Marjo H., and Miia Kivipelto. "Caffeine as a protective factor in dementia and Alzheimer's disease." Journal of Alzheimer's Disease 20.s1 (2010): S167-S174.
- Goldstein, Erica R., et al. "International society of sports nutrition position stand: caffeine and performance." Journal of the International Society of Sports Nutrition 7.1 (2010): 1-15.
- Durrant, Karen L. "Known and hidden sources of caffeine in drug, food, and natural products." Journal of the American Pharmaceutical Association (1996) 42.4 (2002): 625-637.
