Caffeine and energy levels

Caffeine increases energy levels and chases away fatigue, this we all know. It can make the day wonderfully pleasant or support us in work and study. But HOW does it do it! For many people this is a mystery, although the actions have been well researched. It is worth knowing how the substances we take work. That way you can make much better use of their effects and pay attention to interactions with other supplements, drugs or foods.

Wondering how caffeine reduces fatigue? The truth is that it does so in several ways, but one mechanism stands out. It's all about the effect on adenosine receptors.

Inhibition of adenosine activity

Adenosine is a nucleoside that acts as a neurotransmitter. In the brain, its action is to inhibit its activity, which means, among other things, it triggers feelings of fatigue. Adenosine participates in the regulation of sleep and wakefulness rhythms. Its level gradually increases when we are awake during the day, and quickly falls during sleep.

Caffeine and adenosine have very similar structures. This gives them the ability to attach to the same receptors - adenosine receptors. Thus, a competition takes place. Caffeine, when it attaches to the adenosine receptor, prevents adenosine from joining it. More importantly - once attached, it does not cause the same reaction as adenosine. Thus, an antagonism occurs - caffeine blocks adenosine's access to the receptors, so that adenosine cannot induce fatigue.

In a telegraphic summary: caffeine produces exactly the opposite effect to the drowsiness-causing adenosine. This is the main mechanism of caffeine's action occurring even in small doses.

Other mechanisms

Although adenosine antagonism is the predominant property, there are several other pathways that caffeine takes to recharge us with energy. These include:

inhibition of phosphodiesterase (PDE) enzymes,
promoting the release of calcium from intracellular stores,
interacting with GABA(A) receptors,
enhancing the release of dopamine, norepinephrine and acetylcholine.

Caffeine as a pre-workout? An excellent solution!

Caffeine is one of the best-known ergogenics, or substances that increase physical endurance and improve athletic performance. In this context, it seems quite versatile, as it works well for most known sports.

Intense sports activities, especially those performed for long periods of time, can fatigue solidly. The sooner the brain masters fatigue, the sooner the brain will stop sending strong enough signals to the muscles. And muscles need a strong pulse to work at the limit of their endurance. It is in our interest to delay this threshold for the onset of fatigue as much as possible. Caffeine is ideal for this.

Modulating neuromuscular function and enhancing muscle contraction are other benefits of caffeine in sports, which perfectly complement the energizing effects of caffeine, making it a versatile pre-workout supplement.

The ergogenic effect of caffeine does not disappear even with long-term use

We all know that with habitual coffee drinking or the use of caffeine supplements, they no longer work as they did the first time. Over time, sensitivity to its energizing effects simply decreases. One might guess that the same would happen with the impact of sports conditioning. But here's a surprise!

Studies show that in the context of ergogenic action, the effectiveness of caffeine does not disappear even with regular use. True, there may be a slight suppression of the effect, but still , even with long-term and daily intake of caffeine, the ergogenic effect still occurs.

Caffeine addiction

Is caffeine addiction real? Caffeine is the most popular stimulant in the world, so it seems quite innocuous, but addiction as possible. For such a condition we say caffeinism. It usually occurs with long-term intake of caffeine in doses >500 mg per day.

Admittedly, its course is not as severe as with more serious stimulants, but after a long period of caffeine abuse, its withdrawal can cause unpleasant symptoms (fatigue, headache, irritability, etc.). Fortunately, they usually last only a few days.

Symptoms of caffeinism can include:

restlessness and anxiety,
irritability,
excessive agitation,
muscle tremors,
insomnia,
headache,
excessive diuresis,
sensory disturbances,
cardiovascular symptoms,
gastrointestinal complaints (e.g. nausea, vomiting, diarrhea).

The above symptoms can occur not only with long-term caffeine abuse, but also after a single dose when it is too much for the body's ability to metabolize it.

Don't take caffeine too late!

Because of its fatigue-inhibiting effect, caffeine taken too late can make it difficult to fall asleep and impair overall sleep quality. Caffeine circulating in the bloodstream shifts the timing of melatonin secretion in the evening, so we definitely need to avoid it before bedtime.

A universal rule of thumb is to stop taking caffeine at least 6 hours before bedtime. This time may be extended in people who inherently metabolize caffeine slowly. The time it takes to eliminate caffeine from the body also depends on factors such as gender, age, use of oral contraceptives, pregnancy and smoking. Women statistically eliminate caffeine 20-30% faster than men.

As a general rule, the earlier the time of the last caffeine or coffee intake, the better for our sleep.

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