LONDON (Reuters) - The International Olympics Committee (IOC) said on Saturday that 1001 drugs tests have been conducted since the start of the London 2012 Olympic period on July 16.
Of these, 715 were urine tests and 286 were tests on blood.
IOC President Jacques Rogge says a crackdown on doping cheats in the run-up to the London Olympics has been a success, with testers catching more than 100 athletes using performance-enhancing drugs in recent months.
Albanian weightlifter Hysen Pulaku became the first athlete to be ejected from the London 2012 Olympics on Saturday after traces of the anabolic steroid stanozolol were found in his urine sample.
Substances and doping methods are banned when they meet at least two of the three following criteria: enhance performance, pose a threat to athlete health, or violate the spirit of sport.
Following are some of the substances and methods used for doping in sport:
* EPO is a peptide hormone that is produced naturally by the human body. EPO is released from the kidneys and acts on the bone marrow to stimulate red blood cell production.
* By injecting EPO, athletes aim to increase the concentration of red blood cells and consequently their aerobic capacity.
* EPO abuse can lead to serious health risks for athletes. It is well known that EPO, by thickening the blood, leads to an increased risk of several deadly diseases, such as heart disease, stroke, and cerebral or pulmonary embolism. EPO has been implicated in the deaths of several athletes.
* Continuous Erythropoiesis Receptor Activator, or CERA, is a third-generation form of EPO. As opposed to earlier forms of the drug, CERA requires less frequent injection because it has an extended half-life.
* Athletes may take CERA to increase oxygen-carrying capacity to boost endurance. It may also be used after training to encourage swifter recovery.
* Anabolic steroids are drugs that resemble testosterone, a hormone which is produced in the testes of males and, to a much lesser extent, in the ovaries of females.
* Because testosterone and related drugs affect muscle growth, raising their levels in the blood could help athletes to increase muscle size and strength. Athletes who use anabolic steroids also claim they reduce body fat and recovery time after injury.
* Anabolic steroids can cause high blood pressure, acne, abnormalities in liver function, alterations in the menstrual cycle, decline in sperm production and impotence in men, kidney failure and heart disease. They can also make people more aggressive.
* Examples of anabolic steroids include testosterone, stanozolol, boldenone, nandrolone and clostebol.
* Human growth hormone (hGH)- also called somatotrophin or somatotrophic hormone - is a hormone that is naturally produced by the body. It is synthesized and secreted by cells in the anterior pituitary gland located at the base of the brain.
* The major role of hGH in body growth is to stimulate the liver and other tissues to secrete insulin-like growth factor IGF-1. IGF-1 stimulates production of cartilage cells, resulting in bone growth and also plays a key role in muscle and organ growth. All of these can boost sporting performance.
* Commonly reported side effects for hGH abuse are diabetes in prone individuals, worsening of heart diseases, muscle, joint and bone pain, hypertension and cardiac deficiency, abnormal growth of organs and accelerated osteoarthritis.
* Diuretics can be used in a sport as a masking agent to prevent the detection of another banned substance.
* As well as masking other drugs, diuretics can also help athletes lose weight, which they could use to their advantage in sports where they need to qualify in a particular weight category.
* Examples of commonly used diuretics include furosemide, bendroflumethiazide and metolazone.
* Synthetic oxygen carriers, such as haemoglobin-based oxygen carriers (HBOCs) or perflurocarbons (PFCs), are purified proteins or chemicals that have the ability to carry oxygen.
* They are useful for emergency therapeutic purposes when human blood is not available, the risk of blood infection is high or when there is not enough time to properly cross-match donated blood with a recipient.
* The misuse of synthetic oxygen carriers for doping purposes carries the risk of cardiovascular disease in addition to serious side effects such as strokes, heart attacks and embolisms.
* There are two forms of blood doping. Autologous blood doping is the transfusion of one's own blood, which has been stored, refrigerated or frozen, until needed. Homologous blood doping is the transfusion of blood that has been taken from another person with the same blood type.
* Although the use of blood transfusions for blood doping dates back several decades, experts say its recent resurgence is probably due to the introduction of efficient EPO detection methods.
* A test for homologous blood transfusions was implemented at the 2004 Olympic Games in Athens.
* The World Anti-Doping Agency (WADA) says it is funding research into developing a test for autologous transfusions, and it is also leading the development of so-called "biological passports" which keep a record of an athlete's blood and biological variables over time.
* Insulin enhances glucose uptake into the muscle and aids the formation and storage of muscle glycogen. Athletes might use it for events that require high levels of endurance. There is also evidence that it is abused by dopers in conjunction with growth hormones or anabolic steroids to boost muscle growth.
* Misuse of insulin can lead to very low blood sugar levels - a condition known as hypoglycaemia which can lead to the loss of cognitive function, seizures, unconsciousness, and in extreme cases can lead to brain damage of death.
* Advancements in gene therapy for medical reasons mean potential cheats might seek to undergo procedures to modify their genes to enhance their physical capabilities.
* While it is not yet known whether it has ever been done in practice, gene doping could in theory be used to increase muscle growth, blood production, endurance, oxygen dispersal and pain perception.
* Gene doping is defined by WADA as the transfer for nucleic acids or nucleic acid sequences, and the use of normal or genetically modified cells. There are currently no testing methods capable of detecting gene doping.
SOURCES: WADA/Reuters/UK Anti-Doping (UKAD)
Writing by Kate Kelland, additional reporting by Karolos Grohmann, editing by Matt Falloon.