Performance-enhancing drugs

Performance-enhancing drugs are substances used by athletes to improve their performances in the sports in which they engage.

As they have become more widely used and sophisticated, various sports organizations have banned their use, developed testing and enforcement procedures to prevent athletes from using these drugs, and penalized athletes caught using these drugs.

Types of performance-enhancing drugs
Although the phrase performance-enhancing drugs is typically used in reference to anabolic steroids or their precursors, world anti-doping organizations apply the term with a broad brush. The phrase has been used to refer to several distinct classes of drugs:
 * Lean mass builders are used to drive or amplify the growth of muscle and lean body mass, and sometimes to reduce body fat. This class of drugs includes anabolic steroids, beta-2 agonists, and various human hormones, most notably human growth hormone, as well as some of their precursors.
 * Stimulants are used by athletes to stimulate their bodies, usually to increase alertness, decrease fatigue, and/or increase aggressiveness. Examples include caffeine and amphetamines.
 * Painkillers mask athletes' pain so they can continue to compete and perform beyond their usual pain thresholds. blood pressure is increased causing the cells in the muscles to be better supplied with vital oxyen. Painkillers used by athletes range from common over-the-counter medicines such as NSAIDs (like ibuprofen and acetaminophen) to powerful prescription narcotics.
 * Relaxants are sometimes used by athletes in sports like archery which require steady hands and precise aim, and also by athletes attempting to overcome excessive nervousness or discomfort. Alcohol, beta-blockers, and marijuana are examples.
 * Diuretics expel water from athletes' bodies. They are often used by athletes such as wrestlers, who need to meet weight restrictions.  Many stimulants also have a secondary diuretic effect.
 * Masking drugs are used to prevent the detection of other classes of drugs. These evolve as quickly as do testing methods - which is very quickly indeed - although a time-tested classic example is the use of epitestosterone, a drug with no performance-enhancing effects, to restore the testosterone/epitestosterone ratio (a common criterion in steroid testing) to normal levels after anabolic steroid supplementation.

Definition
The classification of substances as performance-enhancing drugs is not entirely clear-cut and objective. As in other types of categorization, there are certain prototype performance enhancers that are universally classified as such (like anabolic steroids), whereas other substances (like vitamins and protein supplements) are virtually never classified as performance enhancers despite their significant effects on athletes' performance. As is usual with categorization, there are borderline cases; caffeine, for example, is considered a performance enhancer by some athletic authorities but not others.

Examples of performance-enhancing drugs include steroids such as cortisone, as well as natural substances such as the athlete's own blood. Using their own blood to enhance their performance, athletes perform what is known as "blood packing", that is, taking around 2 pints of blood from the body 2 weeks prior to the meet, or match that they are training for, and keeping it stored. The night before the big match, they re-inject the blood back into their bloodstream, thereby having 50% more red blood cells, and enabling them to perform better. This method of performance enhancement is almost impossible to detect, unless it is actually witnessed. After the ahtlete is done with his or her sport for the day, the 2 pints are taken out once again and disposed of.