Beta Blockers
Jin Jong-oh

Jin Jong-oh of South Korea competes in the men's 50-meter air pistol event at the 2004 Athens Olympics. Believe it or not, pistol shooters have been known to dope, too.

Ezra Shaw/Getty Images

It's easy to see why baseball players, cyclists, boxers, swimmers and runners sometimes turn to pharmaceuticals for a competitive advantage. These sports require deep reservoirs of muscle strength and endurance -- the very targets of the most popular performance-enhancing drugs. But what about sports like pistol shooting or archery? They certainly demand a keen eye, a steady hand and rock-solid concentration but not Herculean strength. Even so, athletes in these sports may take PEDs. In fact, two North Korean pistol shooters competing in the 1998 Olympic Games in Seoul, South Korea, tested positive for taking propranolol.

As it turns out, propranolol belongs to a class of drugs known as beta blockers, which nonathletes use to control hypertension. Beta blockers work by blocking the effects of epinephrine, a hormone secreted by the adrenal glands that increases blood circulation. People who take beta blockers have a slower heart rate and more relaxed blood vessels, conditions that help reduce blood pressure. But the drugs have an interesting secondary effect: They also mask anxiety by diminishing nervous sweat and trembling, which is exactly why marksmen are drawn to the drugs. If they have a steadier hand, they can perform better in competition. In addition to propranolol, beta blockers include atenolol, acebutolol, alprenolol, bisoprolol and metoprolol, all of which are banned in pistol shooting and archery.