Caffeine is the best-known component of coffee. Its ergogenic function is renowned.

Function

  Caffeine can facilitate athletic performance in several ways:

1. stimulates the activity of the central nervous system, promoting a state of alertness and disposition to activity;
2. modestly increases adrenalin secretion;
3. promotes the retention of immunoglobulins during and after exercise (Bishop, 2006). According to the author of the study, this is an indirect effect of caffeine by increasing adrenalin production;
4. delays the onset and extent of fatigue by acting on receptors for adenosine. More specifically, during chemical energy production, ATP is broken down to release adenosine, which is a carrier of fatigue. By inhibiting the receptors involved in the uptake of this molecule, caffeine helps to reduce the sense of fatigue due to physical exertion;
5. improves muscle contraction strength. More specifically, by improving communication between nerve endings and muscle fibres (which together in physiology are known as motor units), it facilitates their recruitment;
6. it accelerates the mobilisation of fats, making them available as energy sources in the context of aerobic metabolism (also promoting their oxidation with a consequent slimming effect);
7. in some athletes, caffeine intake improves the ability to utilise muscle glycogen;
8. helps keep blood sugar stable;
9. having thermogenic action, it helps maintain a stable body temperature in cold environments.

Negative notes

  Caffeine intake is associated with various adverse effects, most of them affecting the cardiovascular system. More specifically, hypertension and palpitations as well as tremors, agitation and anxiety have been reported. The former is a condition characterised by abnormal blood pressure in the vessels containing it, while palpitations, also known as heart palpitations, involve the heart skipping a beat. Side effects affecting the cardiovascular system can be counteracted by combining caffeine with a theanine product, with dosages ranging from 50mg/day to 200mg/day. For details on theanine, see the relevant section below. Caffeine intake may counteract the strength benefits of creatine products (discussed below). In some athletes the adverse effects are either entirely absent or minor, while in others they are such that they outweigh in salience those that enhance performance. Each athlete has his or her own level of tolerance to caffeine and each should try to work out what his or her own is. Finally, it should be made clear that caffeine is addictive: with repeated intakes, the body’s responsiveness to the same amount of the substance tends to decrease, so an increase in dosage is necessary.

Form and posology

  Caffeine products are mostly available on the market in tabletform. Taking coffee instead of pure caffeine is not recommended. Coffee, in fact, even with the same amount of caffeine taken in a comparison with a pure caffeine supplement, does not have the same effects as the supplement. The reason for this is unclear, but it is assumed to be due to the presence of substances other than caffeine in coffee that have an antagonistic effect on the latter. Therefore, even if the effects of caffeine were to overpower those of its antagonists, these would still tend to limit the stimulating effects of the former. General dosage guidelines assume an intake of 3-6mg of caffeine per kilogram of body weight, but the level of habituation must be taken into account. It should also be considered that the higher the athlete’s performance level, the greater his or her responsiveness to the substance. Therefore, a beginner, with the same tolerance and level of habituation, will need a higher dosage than an expert. As for the best time to take the substance, considering that about 15 minutes after taking caffeine there is an increase in the heart rate, that the maximum increase takes place after about 45 minutes and that it returns to average values after about 90 minutes, it is suggested to ingest the substance about three quarters of an hour before the time when the maximum load is expected. On the other hand, caffeine’s influence on fat mobilisation is at its maximum about three hours after intake, so if you are interested less in the cardiac drive than in providing material for β-oxidation, thus maximising the power of aerobic metabolism, the best time to take it should refer to the latter information, so that the peak load coincides with the peak activity of the substance.