http://en.wikipedia.org/wiki/Beta_block ... nhancementAnxiety and performance enhancement
Officially, beta blockers are not approved for anxiolytic use by the U.S. Food and Drug Administration.[17] However, many controlled trials in the past 25 years indicate beta blockers are effective in anxiety disorders, though the mechanism of action is not known.[18] The physiological symptoms of the fight-or-flight response (pounding heart, cold/clammy hands, increased respiration, sweating, etc.) are significantly reduced, thus enabling anxious individuals to concentrate on the task at hand.
Musicians, public speakers, actors, and professional dancers have been known to use beta blockers to avoid performance anxiety, stage fright and tremor during both auditions and public performances. The application to stage fright was first recognized in The Lancet in 1976, and by 1987, a survey conducted by the International Conference of Symphony Orchestra Musicians, representing the 51 largest orchestras in the United States, revealed 27% of its musicians had used beta blockers and 70% obtained them from friends, not physicians.[19] Beta blockers are inexpensive, said to be relatively safe and, on one hand, seem to improve musicians' performances on a technical level, while some[weasel words] say the performances may be perceived as "soulless and inauthentic."[19]
Since they promote lower heart rates and reduce tremors, beta blockers have been used in professional sports where high accuracy is required, including archery, shooting, golf[20] and snooker.[20] Beta blockers are banned by the International Olympic Committee.[21] A recent, high-profile transgression took place in the 2008 Summer Olympics, where 50 metre pistol silver medallist and 10 metre air pistol bronze medallist Kim Jong-su tested positive for propranolol and was stripped of his medals.
For similar reasons, beta blockers have also been used by stutterers[citation needed] and surgeons.[22]