Copy of L’or noir en randonnée : le café

When it comes to ultralight hiking, one question usually drives gear choices: do I really need it? Can I save a few extra grams in my backpack 🙂

As you may know, the active ingredient in coffee is caffeine, but did you know that it is the same active ingredient in tea, often identified by the name "theine"? Caffeine is a member of the methylxanthine family and is a psychoactive substance.

Although it is often referred to as a stimulant, it actually works by "blocking" the perception of fatigue (adenosine receptor antagonist, for the curious) in the brain. If that sounds complex, just know that it increases central nervous system activity as well as adrenaline and dopamine release 🙂

Caffeine reduces the perception of fatigue, reduces the perception of exertion and pain, and increases work capacity and alertness. These "ergogenic" effects are of interest during physical activities such as hiking as they may contribute to improved performance and reduced fatigue (2) 🙂

In addition, the metabolism of caffeine increases the ability to "break down" (lipolysis) and tap into our fat stores. During long term physical efforts, most of the energy comes from the aerobic system, which can use fatty acids (lipids) and carbohydrates as energy source.

Thus, caffeine allows us tohave more energy available in circulation, which can be interesting for long and tiring hikes.

As for harmful effects, it is often mentioned that coffee is a diuretic. While this is true, its diuretic effect is weak, and caffeine consumption in the form of coffee results in net hydration. In fact, the hydration indices of water and caffeine are not significantly different (3).

Finally, it is important to mention that caffeine, when over-consumed, can cause adverse effects, depending on individual tolerance levels, such as anxiety, tremors, and insomnia 🙂

That's why Health Canada recommends limiting consumption to 400 mg per day for an average adult, the equivalent of about three coffees.