A preliminary verbal command concerning the heaviness of a load can produce a change in the tonus of the working muscles. The words “heavy load” increase the tension of the working muscles while “light load” decreases the tonus of the same muscles. Under certain conditions hypnosis can increase muscular strength by 23% and lower it by 32%.
Thus, correct instructions can have a significant effect on strength if they orient the athlete to execute the movement by emphasizing certain characteristics. Not only must what must be done be explained, but also how it should be done.