This type of use is very difficult of being reproduced in the scientific works for ethical problems. Additionally, the athletes use use drugs veterinarian, whose toxicity human being not yet was studied (FORBES, BROMSTOM and COLLINS, 1993). He must yourself be added that the performance of the athlete is more difficult to evaluate to the measure that the level of the athlete increases, therefore minimum difference in speed as 1%, can make deep difference in terms of international competition. Another mechanism aventado for action in athlete is decurrent of the effect propitiated for esterides anablicos on comportamentto, as the euphoria, to little sensation of fatigue, the sensation of well-being, what it could will make possible a training with greater intensity, leading the increase of muscular mass and to determine the improvement of the performance (WILSON & GRIFFIN, 1980; LABREE, 1991). Another cogitated mechanism mentions the fact to it of esterides anablicos to be able to act on the hematcrito and sanguineous volume (MOORADIAN et al, 1987; WILSON, 1988), what he can have effect on the performance.
Although the reduction of the fatigue after exercise to be cited as mannering effect, exists scientific base for this, since esterides anablicos can antagonizar the effect of glicocorticides and is set free in abundance during and after physical exercise (ROGOL & YESALIS, 1992). Eventually, esterides can show different effect between the individuals, since individual differences in the sinergismo with the hormone of the growth and tiroxina exist, or differences in the amount and quality of the hormonal receiver in the esqueltico muscle, that can contribute for the different effect on the mass and the muscular force (LAMB, 1990). All these presented factors they make with that doubts remain regarding the real effectiveness of esterides. Moreover, it has studies that they show improvement of the performance in the period has controlled, what would really speak in favor of the psychological effect.