Scientific study of antiasthmatics (Clenbuterol) action on athletes either does not fix an anabolic effect at all or weight gain is so small that it can be ignored. And we are talking about serious researches, carried out on behalf of the International Olympic Committee. Such investigations were needed to resolve the question about antiasthmatics (Clenbuterol) inclusion into the doping list. Scientists have been experimenting with pills, sprays, combined different drugs to enhance the effect, but the result was always the same – no result! The only thing that was confirmed for sure is the side effects of antiasthmatic drugs (Clenbuterol) for the heart. We refer to those megadoses of antiasthmatics (Clenbuterol) which athletes use. However another thing is much more interesting. A 40-year-old bodybuilder, who suffered from asthma, consulted a doctor complaining for a clear deterioration of after training state after taking antiasthmatic medication. Investigation of the blood showed that there is a high level of special enzymes – creatine kinase type MM in the bodybuilder’s blood. This enzyme causes the destruction of muscle tissue. When the bodybuilder due to the doctor’s advice stopped using antiasthmatic beta-2-blockers, creatine kinase levels returned to normal, and the general state of the bodybuilder improved. It is clear that this fact can not serve as a basis for conclusions about the potential harms of antiasthmatics (Clenbuterol), but it makes one wonder. In any case, every bodybuilder should know that antiasthmatics (Clenbuterol) adversely affect the exchange of potassium, increasing its excretion from the body. It turns out that the recommended method of Clenbuterol intake before competitions is potentially dangerous, because it is superimposed on the potassium-depleted pre-event diet and (often) diuretics use, increasing potassium excretion with urina. But an acute shortage of potassium means cramping, weakness, loss of consciousness.