Imagine there would be something that boosts your brainpower, makes you feel like you want to run a marathon, is cheap and  proven by science. Interested? Then let me introduce you to caffeine and the reason why so many people drink coffee on a regular basis, but don´t get a response from it.

The problem is that they violate almost every rule there is about consuming caffeine. “Rules?,” you might think. Yes, rules and there is even more to it… In this article I will boil down the science of caffeine and craft it to 2 simple rules. Those two strategies will allow you to enhance your cognitive capacity by avoiding to get tolerant to caffeine.

How caffeine works

The benefits of caffeine start at doses as low as 40mg and range up to 300mg (0,5mg – 4mg per kg bodyweight)[1] [2]. This equals roughly 50ml – 330ml coffee. When I read this first I couldn´t believe that just 40mg of caffeine can cause measurable effects. However, the reason why most people don´t get a response from such dosages is that they´re tolerant to it. But more on this later.

Caffeine works by suppressing tiredness and by increasing your arousal. Therefore, we can think of its effectiveness like a U-shaped curve. You have likely witnessed this yourself. When you drink too much coffee, there is a point where you start to feel jittery, restless and stressed. And that´s what the Yerk-Dodson-law states:

[1]A review of caffeine’s effects on cognitive, physical and occupational performance:

[2] Lerenza S. Colzato: “Theory-Driven Approach to Cognitive Enhancement”

What we can draw from this is:  too much caffeine => too much stress => decreased cognitive performance. However, the point where returns start to diminish is unclear and highly individual. In my experience you get a sort of feeling when you are about to have had enough.

What are the exact numbers?

Unfortunately, we cannot consume 300mg (two big cups of coffee) on a regular basis and feel always energized. That´s what most people try and fail with all the time. As most regular coffee drinkers now, tolerance develops quickly. This is why the results of studies differs compared to what we experience in everyday life. The benefits of caffeine are only observed in light or non-habitual users. For the sake of emphasize, let me repeat that: the benefits of caffeine are only observed in light or non-habitual users.

Cognitive performance increases occur only when you are not tolerant to the substance. If you are a regular user however, the only thing that happens is that your mood gets elevated.[1] Research also tells us that drinking roughly two middle sized cups of coffee per day (3mg per kg or 225mg) across a few weeks, you will become completely physically tolerant [2]. By the way, at dosages as low as 100mg per day you already get addicted [3].

For clarification, a light user is defined as someone who stays under 100mg (1,5mg per kg bodyweight) per day and a regular user is stated as someone who consumes more than 150mg (2mg per kg bodyweight) per day. And here is the sweet spot. As I mentioned previously, the benefits of caffeine start already at 40mg. Hence, my first proposal is:

  • Consume only 100mg of caffeine on a daily basis

But what if you need to a bigger boost? Conveniently, it has been shown that just 25mg alone are enough to block most withdrawal symptoms[3] like decreased concentration, fogginess, …                  This leads us to my alternative strategy:

  • Consume 30mg for 5 days and on two days 225mg, per week

To summarize this section: very low doses can boost your performance because you don´t develop tolerance.

[1] Lerenza S. Colzato: “Theory-Driven Approaches to Cognitive Enhancement”:

[2] Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine:

[3] A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features:

Why you should implement those strategies

If you can reduce your consumption as suggested, here are the merits. Under the condition that you are a light user, caffeine has been proven to increase alertness, wakefulness, arousal, mood, vigilance, attention, reaction time, sport performance and working memory capacity. Attention and working memory capacity (WMC) are especially awesome.

Let me explain. WMC is a system, identified as essential for problem solving or the execution of complex cognitive tasks.[1] Think of it like the processor of a computer, the faster it is, the more programs can be run simultaneously. A concrete example for when you need working memory, is writing a text. You need to hold different chunks of information in mind at the same time and process them into a comprehensive format.

Increased attention means that you can concentrate longer and become immersed with a task more quickly. To illustrate this, consider you are a student in a lecture. With higher attention levels your brain wanders less often during the lecture, meaning you´re getting a better understanding of the topic and you can remember more information from it.

In short, caffeine boosts your brainpower, makes you more productive and feels good.


When to consume caffeine and how to not mess up your sleep

First let us get this one straight: Getting enough sleep is not negotiable. If you are sleep deprived, you won´t only destroy your health in the long run. You will also be less productive, less successful in sports and primed for fat gain. For example, after 10 nights of 6 hours of sleep people had the same attention capacity as someone who pulled an allnighter![1]

With this in mind, consider this study: When participents got 400mg caffeine 6 hours before they were going to bed, their sleep quality was measurably disrupted.[2] Furthermore, caffeine has an half-life of 5-7 hours. So if you consume 200mg caffeine at 2 p.m., there are still 75mg in your body when you´re going to bed at 11 p.m.

Some people metabolize caffeine even slower (including me), which brings us to the fact that your genes influence how you can handle the substance. In other words, how you respond to caffeine, is highly individual and determined by your genes.

Taken together, the insight to consume caffeine as early as possible, should become obvious. It is way more important to be well rested for your productivity, brainpower and well being, than is a little boost of caffeine!

So should you consume it right after waking up? Unfortunately, I have to ask you to defer your morning cup of coffee by around 2 hours after you left your bed. This is crucial, because caffeine increases your mental performance by increasing your cortisol and adrenaline levels. (This is why your arousal level gets elevated) However, right after waking up, cortisol and adrenaline are already at high levels naturally. Therefore, coffee won´t do much for you except nudging up your caffeine tolerance by that time.[3] [4] Because of this, wait around 2 hours after you´re awaken until you consume caffeine, when stress hormones have sunken back to baseline.

Now before you experiment yourself with my recommendations, I want to come back to something I mentioned previously. I know myself that it is hard to stay under 100mg per day because it´s just so tempting to consume “just one more” cup of coffee. If you should find yourself overdosing every time, then remember that you don´t have to use caffeine when you can´t deal with it. It is totally fine to abandon the substance, because in the end it is what it is: another addictive drug

[1] Matthew Walker: “Why we sleep”

[2] Caffeine Effects on Sleep Taken 0, 3, or 6 Hours before Going to Bed:

[3] Michael Breus: “The Power of WHEN” :

[4] Jake Knapp and John Zeratsky: “Make Time: How to focus on what matters every day” :

Featured Image by Nathan Dumlao on Unsplash

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