Performance-enhancing drugs (PEDs) are drugs that improve active performance in humans, known colloquially in sports as ‘doping’.
Perhaps the most famous abuser of PEDs to date is Lance Armstrong, a seven-time Tour de France champion, who in 2013 confessed to using performance-enhancing drugs during his cycling career, and was stripped of the seven Tour de France titles he won from 1999 to 2005. More recently, Maria Sharapova has tested positive for Meldonium, an anti-ischamic drug used to treat neurological disorders. This has resulted in her ban from tennis for two years, including the Olympic Games.
The use of performance-enhancing drugs in sports can be traced back as far as the 8th century CE Olympic Games when Greek Olympians are believed to have eaten sheep testicles to boost energy levels.
Goldman’s Dilemma was posed to elite Athletes by physician and author of “Death in the Locker Room”, Robert Goldman. He asked athletes whether they would take a drug that would guarantee them overwhelming success in sport, but would cause them to die after five years. He found that approximately half of the athletes stated that they would take the drug.
In the United States, there are an estimated three million anabolic-androgenic users of whom 60% are non-competitive recreational bodybuilders or non-athletes, who use these drugs for cosmetic purposes. The most recent data from the British Crime Survey 2010 estimates that in the United Kingdom 226,000 people in the 16-59 age group admitted to having used anabolic steroids, with 19,000 using them in the past month. The figures are likely to be a gross under estimation. PED misuse is not unique to adults and steroid abuse prevalence has also been reported in teenagers.
So what are the implications of PEDs – both on professional athletes and amateurs?
The big players
Anabolic steroids are available commercially. They are popular with sprinters, weight lifters, and body builders. They are similar in structure to the male sex hormone (testosterone) and therefore they enhance male reproductive and Secondary Sex Characteristics, allowing athletes to train harder and longer. In addition, they increase muscle mass and strength.
The main systems affected are the secondary sex characteristics, the heart, and the liver. In men, anabolic steroids may interfere with normal sex function, resulting in baldness, infertility, and gynaecomastia. In women, it may cause male characteristics to develop. There is an increased risk of heart attacks and strokes. Users are also prone to dependence and behavioral outbursts also known as “roid rage”.
Protein hormones: human growth hormone (HGH), insulin like growth factor (IGF-1), and insulin
HGH is produced naturally by the body and is important for growth and development in adolescence. It stimulates an increase in muscle mass and bone strength, and reduces body fat. It is a popular PED as it is difficult to detect. An artificially increased level of this hormone is detrimental. HGH is associated with acromegaly and enlargement of organs such as the kidneys, liver, and tongue, as well as heart disease, diabetes mellitus, impotence and osteoporosis.
IGF-1 stimulates protein and bone synthesis, and has a similar side effect profile to HGH.
Insulin is important in the breakdown of carbohydrates, fat, and protein and can be used in combination with anabolic steroids or HGH to promote muscle mass by further stimulating growth. High dose insulin can lead to hypoglycaemia, nausea, shaking, and weakness, which may then progress to coma and death.
Erythropoietin (EPO) and blood doping
These PEDs are used to increase delivery of oxygen to exercising tissues. Recombinant human erythropoietin (rHuEPO) is a hormone normally secreted from the kidneys. It is popular with endurance athletes, such as cyclists, and marathon runners. EPO stimulates bone marrow to increase the number of red Blood cells in the body. This increases oxygen carriage by as much as 7-10%. It can be tested for in the blood and urine, but is removed from the body within a short time making detection difficult.
The increase in Red Blood Cells from use of these PEDs leads to sludging of blood through blood vessels. The heart has to work harder, which increases the risk of a heart attack. In the brain, sludging reduces blood flow, significantly increasing the risk of a stroke. In addition, users may develop a reaction to rHuEPO and it has been associated with sudden death during sleep in a number of pro cyclists.
Blood doping is the practice of infusing whole blood into an athlete. It has a similar effect to training at high altitude and is also popular with endurance athletes. Risks are the same for non-athletic blood transfusion patients, in particular the risk of acquired viral infections and blood volume overload. There is currently no guaranteed way to detect blood doping.
The new kids on the block
New undetectable forms of erythropoietin, genetic doping, and xenon
There are a number of different forms of erythropoietin, EPO-alpha, beta, delta, omega, and zeta are the most common in clinical use. EPO Z (Zeta), currently undetectable in urine, was patented in Italy by Aifa, an Italian medicines agency, in September 2010. The Chinese have also manufactured an undetectable form of EPO.
Gene therapy, usually used to treat diseases, is also being utilized by athletes in genetic doping. This technology makes use of synthetic substances to manipulate the muscle building gene to enhance performance.
Xenon is a noble gas commonly used as an anaesthetic agent, but in sports its use has been associated with endurance athletes. Xenon binds to a specific region of the DNA and boosts erythropoietin levels. It first came to light in the 2014 Winter Olympics when it was revealed that Russian skiers were using it to increase the O2-carrying capacity of their blood.
Recent events have highlighted the extent of PED use in sport. To keep doping in check, we may have to resort to severe measures, such as with the expulsion of the Russian team from the Brazilian Olympics, 2016. However, this does seem unfair to those athletes who do not use PEDs and train hard.
With the drive for faster times and the demands placed on athletes for higher placement, however, I think the future will lead to cleaner, undetectable PEDs rather than cleaner players.
Featured image credit: Twilight cyclists by weesun. CC0 Public Domain via Pixabay.
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