Lance Armstrong has admitted to a host of sporting crimes in his tell-all interview with Oprah Winfrey — but what does it all mean?
Performance enhancement has come a long way from the days of just popping pills. Armstrong's cheating methods included a number of complex strategies you may have heard but not understood. Here is our guide to some of the terms.
EPO and blood doping
Blood doping is the practice of boosting the number of red blood cells in the bloodstream in order to enhance athletic performance.
Because blood cells carry oxygen from the lungs to the muscles, a higher concentration can improve an athlete's aerobic capacity (known as VO2 max).
Erythropoietin, or EPO, is a hormone that controls red blood cell production in the body.
Armstrong used EPO to raise his red blood cell count, which increases the amount of oxygen that can be delivered to muscles, improving recovery and endurance.
Although EPO has been banned since the 1990s, the first screening test wasn't used until the 2000 Summer Olympic Games in Sydney.
There are two ways to do it.
One, red blood cells from a donor are harvested, concentrated and then transfused into the athlete's blood prior to endurance competitions.
The other uses the athlete's own red blood cells which are harvested well in advance of competition, concentrated and then re-introduced before an event.
Both methods can have dangerous side effects.
"The story was perfect": Lance Armstrong's confession
Detection and masking
Blood doping is more difficult to identify than drugs or hormone levels.
There are two ways officials can determine if the blood sample has been taken from a doping athlete.
The first is if they find an unusually high value of red blood cells.
A newer measure is to determine the age of the red blood cells. If an athlete has concentrations of both young and mature red blood cells it suggests some have been introduced artificially.
Saline and plasma transfusions are illegal in sport when they are used to mask blood doping because they alter the concentration of red blood cells and haemoglobin.
The Union Cycliste Internationale (UCI) imposes a 15-day suspension from racing on any male athlete found to have an mature red blood cell count above 50 percent and hemoglobin concentration above 17 grams per decilitre.
Corticosteroids, or cortisone, is a man-made performance enhancing drug like cortisol.Cortisol is known as the stress hormone. Corticosteroids work to decrease inflammation that can cause swelling and pain, according to the Cleveland Clinic research centre.
They can be administered locally to the specific area that hurts, systemically through a pill or intravenously.
Corticosteroids come with a long list of side effects including weight gain, sudden mood swings, blurred vision, osteoporosis and high blood pressure.
Testosterone is a natural hormone that helps regulate bone density, fat distribution, muscle strength, red blood cell production and sex drive, according to research from the Mayo Clinic. It is found in higher quantities in men but is also present in women.
Athletes abuse testosterone to build muscle mass and power and it also increases the body's red blood cell count.
Testosterone perpetuates the popular assumption that steroids affect male genitals because abusing it shuts down the body's natural production of the hormone and can cause the testicles to shrink.
Human Growth Hormone
Human growth hormone or HGH Growth hormone is used as a prescription to treat children's growth disorders and adult growth hormone deficiency.
It is used illegally in sport to increase strength and lean muscle mass, to assist in weight loss and promote recovery.
Author: Philippa Lees
Approving editor: Rory Kinsella.