How Performance-enhancing Drugs Work

Every two years as the Olympic Games begin, we hear about athletes using or at least being tested for performance-enhancing drugs. Every time the Tour de France rolls around, there's talk of possible doping. Sometimes, competitors raise the question when one athlete does particularly well. Other times, tests catch athletes with drugs in their systems. The practice of using artificial substances or methods to enhance athletic performance is called doping. Doping has become such a great concern that the United States formed an Anti-Doping Agency.
We will discuss why some athletes take drugs, what the major classes of drugs and their side effects are and how drug use is tested for.­

How strong are you?

You'd probably be amazed to learn how much force your body's joints and muscles actually support on a daily basis. This interactive segment from Discovery takes you inside the body and explains how much strength your bones and muscles really possess. Other activities let you explore even more of your body's systems to see exactly how they move you through your daily life

Why Some Athletes Use Drugs

Athletes face enormous pressure to excel in competition. They also know that winning can reap them more than a gold medal. A star athlete can earn a lot of money and a lot of fame, and athletes only have a short time to do their best work. Athletes know that training is the best path to victory, but they also get the message that some drugs and other practices can boost their efforts and give them a shortcut, even as they risk their health and their athletic careers.
As far back as ancient Greece, athletes have often been willing to take any preparation that would improve their performance. But it appears that drug use increased in the 1960s. One well-publicized incident happened at the Seoul Olympics in 1988 when sprinter Ben Johnson tested positive for anabolic steroids and was stripped of his gold medal. Athletes may also misuse drugs to relax, cope with stress or boost their own confidence.
Athletes may have several reasons for using performance-enhancing drugs. An athlete may want to:

Build mass and strength of muscles and/or bones

Increase delivery of oxygen to exercising tissues

Mask pain

Stimulate the body

Relax

Reduce weight

Hide use of other drugs

The classes of drugs used for these purposes are shown above. Most of the drugs shown are banned outright in Olympic competitions. However, some of these drugs, such as cortisone and local anesthetics, are restricted in Olympic competition because they have legitimate clinical uses. We'll look at each major class of drug and tell you about the dangerous side effects.

Building Mass and Strength
Mass- and strength-enhancing drugs used by athletes include:

Anabolic steroids

Beta-2 agonists

Human chorionic gonadotropin (hCG)

Luteinizing hormone (LH)

Human growth hormone (hGH)

Insulin-like growth factor (IGF-1)

Insulin

Anabolic Steroids
A steroid is a chemical substance derived from cholesterol. The body has several major steroid hormones -- cortisol and testosterone in the male, estrogen and progesterone in the female. Catabolic steroids break down tissue, and anabolic steroids build up tissue. Anabolic steroids build muscle and bone mass primarily by stimulating the muscle and bone cells to make new protein.
Athletes use anabolic steroids because they increase muscle strength by encouraging new muscle growth. Anabolic steroids are similar in structure to the male sex hormone, testosterone, so they enhance male reproductive and secondary sex characteristics (testicle development, hair growth, thickening of the vocal cords). They allow the athlete to train harder and longer at any given period.
Anabolic steroids are mostly testosterone (male sex hormone) and its derivatives. Examples of anabolic steroids include:

Testosterone

Dihydrotestosterone

Androstenedione (Andro)

Dehydroepiandrosterone (DHEA)

Clostebol Nandrolone

These substances can be injected or taken as pills. Anabolic steroids have a number of possible and well-known side effects, including: Jaundice and liver damage because these substances are normally broken down in the liver Mood swings, depression and aggression because they act on various centers of the brain In males, the excessive concentrations interfere with normal sexual function and cause:
Baldness

Infertility

Breast development

In females, the excessive concentrations cause male characteristics to develop and interfere with normal female functions. The drugs can:
Stimulate hair growth on the face and body Suppress or interfere with menstrual cycle, possibly leading to infertility Thicken the vocal cords, which causes the voice to deepen, possibly permanently If pregnant, interfere with the developing fetus
Beta-2 Adrenergic Agonists
When inhaled, beta-2 agonists relax the smooth muscle in the airways of asthma patients by mimicking the actions of epinephrine and norepinephrine, substances that are secreted by sympathetic nerves. However when injected into the bloodstream, these drugs can build muscle mass (anabolic effect) and reduce body fat (catabolic effect). The anabolic effect appears to directly affect building proteins in the muscles, which is independent of nervous or cardiovascular effects. Some examples of beta-2 agonists include:

Clenbuterol

Tertbutaline

Salbutamol

Fenoterol

Bambuterol

Some of these substances are permitted in inhaler forms with written medical consent. The major side effects include:
Nausea, headaches and dizziness because these substances constrict blood vessels in the brain Muscle cramps because they constrict blood vessels in muscles

Rapid heart beats or flutters because they stimulate heart rate

Masking Pain
Along with training and performing to be a world-class athlete comes the pain of injuries. Sometimes, athletes try to mask their injury pain with drugs, including narcotics, protein hormones, cortisone and local anesthetics.
Narcotics

Narcotics are used to treat pain and include substances such as morphine, methadone and heroin. Narcotics are highly addictive, and the "high" associated with their use can impair mental abilities (judgment, balance and concentration). Also, athletes who continue to compete with an injury run the risk of further damage or complications.
Protein Hormones

Adrenocorticotrophic hormone (ACTH) is a naturally occurring protein hormone that is secreted by the pituitary gland and stimulates the production of hormones from the adrenal cortex. These adrenal cortex hormones are important in reducing inflammation in injuries and allergic responses. So, by using ACTH to stimulate internal adrenal cortex hormones, an athlete could mask an injury. Possible side effects include stomach irritation, ulcers, mental irritation and long-term effects (weakening bones and muscles).
Cortisone

Cortisone is one of the adrenal cortex hormones. Clinically, it is injected to reduce inflammation in injuries and allergic responses. The advantages and side effects of its use are the same as with ACTH.
Local Anesthetics

Local anesthetics, like those used by your dentist or doctor, are used to mask pain in the short-term without impairing mental abilities. They include novocaine, procaine, lidocaine and lignocaine. Athletes may use them so that they can continue to compete while injured. The major problem with their use is the possibility of further aggravating an injury.
Testing Athletes for Drug Use
The majority of drugs that can be used by athletes can be detected in samples of urine. An athlete is told by a drug control officer to submit a urine sample for testing. The sample is then sent to a laboratory for analysis and the results are reported back to the governing athletic agency. For some substances, blood samples may be required.

Gas Chromatography/Mass SpectrometryGas
chromatography and mass spectrometry are the most common methods of chemical analysis. These tests can be done on urine and blood samples. In gas chromatography, the sample is vaporized in the presence of a gaseous solvent and placed through a long path of a machine. Each substance dissolves differently in the gas and stays in the gas phase for a unique, specific time, called the retention time. Typically the substance comes out of the gas and is absorbed on to a solid or liquid, which is then analyzed by a detector. When the sample is analyzed, the retention time is reported or plotted to create a chromatogram. Standard samples of drugs are run, as well as the urine/blood samples, so that specific drugs can be identified and quantified in the chromatograms of the urine/blood samples.
In mass spectrometry, samples are blown apart with an electron beam and the fragments are accelerated down a long magnetic tube to a detector. Each substance has a unique "fingerprint" in the mass spectrometer. Again, standard samples are run for identification and quantification of drugs in the urine/blood samples.
Immuno-Assays
Some substances (such as hCG, LH, ACTH) can be measured in urine samples using an immuno-assay. In this test, the sample is mixed with a solution containing an antibody specific to the tested substance. An antibody is a protein that binds only a specific substance and is how the body recognizes foreign substances. The antibody in the test is usually tagged with a fluorescent dye or radioactive substance. The amount of fluorescent light or radioactivity is measured and is related to the concentration of the tested substance in the sample.
Tests Under Development
Currently, there are no reliable tests for hGH, IGF-1 and EPO. However, a test for EPO is being developed. The EPO test looks at the size of red blood cells. It has been noticed that synthetic EPO produces red blood cells that are smaller and bind more iron then natural EPO. So, the size and iron content of red blood cells from a blood sample are analyzed to determine whether an athlete has used EPO.
Although there is little statistical evidence on how widespread doping is, athletes and coaches stress that most competitors do not take drugs. Nonetheless, drug testing is becoming an increasingly integral part of sports competitions. As new performance-enhancing drugs are developed, new tests are developed to detect these drugs, and the struggle to keep sports clean continues indefinitely.