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For the month of May, Train Time team would like to focus on coffee! Subject to debate, coffee enjoys a divergent popularity. Faulted for its caffeine content, it is however for it that it is consumed. So is it good or bad? This question that has not been asked?

What is its main physiological action?
Coffee is mainly known for the caffeine it contains. This binds to receptors antagonistic to adenosine, a molecule naturally secreted during a state of fatigue. So, by blocking these receptors, you don’t feel tired. On the contrary, by stimulating the central nervous system, caffeine gives a boost of energy until it is destroyed and the accumulated adenosine molecules bind to their receptor. It’s the free fall, the “coup de barre”, in short the moment you say to yourself: I need a new coffee!

What are its virtues?
Coffee is known for its stimulating properties. It increases your alertness, increases your faculties of concentration and makes you overall more efficient. We understand that these virtues are attractive and why it is so difficult to resist them. Caffeine is a bronchodilator and increases respiratory flow. Thus the capture of oxygen by the respiratory tract is more important and the stimulation of the cardiac output accelerates its circulation in the organism. It also stimulates the mobilization of fats for energy purposes. By increasing the consumption of oxygen and the use of fats as an energy source, everything leads us to believe that coffee would be an ideal drink for the endurance sportsman! Caffeine stimulates the secretion of adrenaline. It is recognized that its consumption changes the perception of effort by reducing the feeling of pain. These data are of course subjective. We don’t all respond the same way to caffeine, whether it’s the intensity of its effect or the duration of action.

Coffee also contains a multitude of phenolic compounds assimilated to antioxidants. Antioxidants are molecules that protect cells from oxidative stress generated, among other things, during intense sports training. Coffee would therefore have protective properties.

What are its harms?
At first glance, coffee seems to be a drink of all virtues. This is without taking into account the inconvenience it can cause.

Exceeding the threshold of 3 to 4 coffees per day can cause sleep disturbances ranging from simple agitation to insomnia. Either way, even the smallest sleep disturbance affects recovery in athletes wishing to perform. It is not uncommon to be confronted with individuals whose only 2 coffees consumed during the day affect sleep.

Acting on the central nervous system, coffee has a diuretic action and accelerates intestinal transit. However, in athletes, the level of hydration is correlated with the level of effort that can be provided. A loss of 1% of body hydration is equivalent to a 10% drop in the level of effort. We will also think about the fact that coffee accelerates intestinal transit and accentuates the acceleration naturally caused by exercise. Coffee is, in this case, difficult to reconcile with the digestive comfort of athletes during their activity.

In addition, caffeine stimulates digestive secretions, including the secretion of hydrochloric acid by the stomach. In some people, drinking coffee can lead to heartburn, acid spikes … or simply poor digestion of a meal if it is taken during it.

We also recognize caffeine, the ability to modify the ionic fluxes of calcium and potassium involved in muscle contraction. The stimulating effect of caffeine may not be correlated with an improvement in physical capacity. Again, it’s all about individual tolerance.