Athletes seeking to avoid testing positive use various methods. The most common methods include:

- Urine replacement, which involves replacing dirty urine with clean urine from someone who is not taking banned substances. Urine replacement can be done by catheterization or with a prosthetic penis such as The Original Whizzinator.

- Diuretics, used to cleanse the system before having to provide a sample.

- Blood transfusions, which increase the blood's oxygen carrying capacity, in turn increasing endurance without the presence of drugs that could trigger a positive test result.

The Lance Armstrong doping case was a doping investigation that led to American former professional road racing cyclist Lance Armstrong being stripped of his seven Tour de France titles and his eventual admission to the doping.

Doping in Russian sports has a systemic nature. Russia has had 51 Olympic medals stripped for doping violations – the most of any country, four times the number of the runner-up, and more than a third of the global total. From 2011 to 2015, more than a thousand Russian competitors in various sports, including summer, winter, and Paralympic sports, benefited from a cover-up.

Side effects in women include:

- hair loss

- male pattern baldness

- hypertrophy of the clitoris

- increased sex drive

- irregularities of the menstrual cycle

- development of masculine facial traits

- increased coarseness of the skin

- premature closure of the epiphysis

In countries where the use of these drugs is controlled, there is often a black market trade of smuggled or counterfeit drugs. The quality of these drugs may be poor and can cause health risks. In countries where anabolic steroids are strictly regulated, some have called for a regulatory relief. Steroids are available over-the-counter in some countries such as Thailand and Mexico.

The 2007 Tour de France was affected by a series of scandals and speculations related to doping. By the end of the Tour, two cyclists were dismissed for failing tests and the wearer of the yellow jersey was voluntarily retired by his team for lying about his whereabouts and missing doping tests. A fourth rider was confirmed to having used doping while in a training session prior to the 2007 Tour and a fifth rider failed tests late in the race, with his result being officially announced just after the end of the Tour. During the competition, two teams were asked to withdraw after at least one member was found to have doped.

The events generated criticism and a general distrustful attitude toward the sport of professional cycling from media and public opinion. The doping allegations also resulted in several team sponsors threatening to retire their support if events advanced further. Some media such as German TV channels ARD and ZDF left the Tour once the first scandals broke. Following the Tour's conclusion, the sport's governing bodies spoke out about ways to combat the prevalence of doping in cycling and key team sponsors elected to withdraw their support due to the reputational damage caused by the scandals. The 2007 Tour de France has been referred to as one of the most controversial Tours. After the end of the Tour, "The Times" of London ranked it 4th in its list of the top 50 sporting scandals.

For much of the second phase of his career, Cyclist Lance Armstrong faced constant allegations of doping. Armstrong consistently denied allegations of doping until a partial confession during a broadcast interview with Oprah Winfrey in January 2013.

Cheating at the Paralympic Games has caused scandals that have significantly changed the way in which the International Paralympic Committee (IPC) manages the events.

Testing for performance-enhancing drugs has become increasingly strict and more widespread throughout the Games, with powerlifting seeing the most positive results. Competitors without disabilities have also competed in some Paralympic Games, with the Spanish entry in the intellectually disabled basketball tournament at the 2000 Summer Paralympics being the most controversial.

There have been allegations of doping in the Tour de France since the race began in 1903. Early Tour riders consumed alcohol and used ether, among other substances, as a means of dulling the pain of competing in endurance cycling. Riders began using substances as a means of increasing performance rather than dulling the senses, and organizing bodies such as the "Tour" and the International Cycling Union (UCI), as well as government bodies, enacted policies to combat the practice.

Use of performance-enhancing drugs in cycling predates the Tour de France. Cycling, having been from the start a sport of extremes, whether of speed by being paced by tandems, motorcycles and even cars, or of distance, the suffering involved encouraged the means to alleviate it. Not until after World War II were sporting or even particularly health issues raised. Those came shortly before the death of Tom Simpson in the Tour de France of 1967. Max Novich referred to the Tour de France in a 1973 issue of "New York State Journal of Medicine" as "a cycling nightmare". In the eyes of a 1998 German observer:

Tetraphobia (from Greek τετράς—"tetras", "four" and φόβος—"phobos", "fear") is the practice of avoiding instances of the number . It is a superstition most common in East Asian nations.

States that agree to the Convention align their domestic rules with the World Anti-Doping Code, which is promulgated by the World Anti-Doping Agency. This includes facilitating doping controls and supporting national testing programmes; encouraging the establishment of "best practice" in the labelling, marketing, and distribution of products that might contain prohibited substances; withholding financial support from those who engage in or support doping; taking measures against manufacturing and trafficking; encouraging the establishment of codes of conduct for professions relating to sport and anti-doping; and funding education and research on drugs in sport.

Ladan and Laleh Bijani (in Persian: ) (January 17, 1974 – July 8, 2003) were Iranian conjoined twin sisters. They were joined at the head and died immediately after their complicated surgical separation. Coincidentally, the twins were born 100 years to the day of the deaths of Chang and Eng Bunker, also conjoined twins, famously known as the "original" Siamese twins.

The World Anti-Doping Agency (WADA) is the main regulatory organization looking into the issue of the detection of gene doping. Both direct and indirect testing methods are being researched by the organization. Directly detecting the use of gene therapy usually requires the discovery of recombinant proteins or gene insertion vectors, while most indirect methods involve examining the athlete in an attempt to detect bodily changes or structural differences between endogenous and recombinant proteins.

Indirect methods are by nature more subjective, as it becomes very difficult to determine which anomalies are proof of gene doping, and which are simply natural, though unusual, biological properties. For example, Eero Mäntyranta, an Olympic cross country skier, had a mutation which made his body produce abnormally high amounts of red blood cells. It would be very difficult to determine whether or not Mäntyranta's red blood cell levels were due to an innate genetic advantage, or an artificial one.

The International Convention against Doping in Sport is a multilateral UNESCO treaty by which states agree to adopt national measures to prevent and eliminate drug doping in sport.

14 of the 25 most recent winners (56%) have either failed tests or have confessed to have used doping. Together with those who failed tests but never sanctioned, 68% of the winners evidently used doping as detailed in the table below.

The "British Medical Journal" reported in a study that looked at mortality statistics in the United States over a

25-year period. They found that on the fourth day of the month, Asian people were thirteen percent more likely to die of heart failure. In California, Asians were twenty-seven percent more likely to die of a heart attack on that day. The purpose of the study was to see if psychological stress caused by belief in this superstition could indeed trigger deadly heart attacks and other fatal incidents.

As astronauts frequently have motion sickness, NASA has done extensive research on the causes and treatments for motion sickness. One very promising looking treatment is for the person suffering from motion sickness to wear LCD shutter glasses that create a stroboscopic vision of 4 Hz with a dwell of 10 milliseconds.

Over-the-counter and prescription medications are readily available, such as dimenhydrinate, scopolamine, meclizine, promethazine, cyclizine, and cinnarizine. Cinnarizine is not available in the United States, as it is not approved by the FDA. As these medications often have side effects, anyone involved in high-risk activities while at sea (such as SCUBA divers) must evaluate the risks versus the benefits. Promethazine is especially known to cause drowsiness, which is often counteracted by ephedrine in a combination known as "the Coast Guard cocktail.". There are special considerations to be aware of when the common anti-motion sickness medications are used in the military setting where performance must be maintained at a high level.

Scopolamine is effective and is sometimes used in the form of transdermal patches (1.5 mg) or as a newer tablet form (0.4 mg). The selection of a transdermal patch or scopolamine tablet is determined by a doctor after consideration of the patient's age, weight, and length of treatment time required.

Many pharmacological treatments which are effective for nausea and vomiting in some medical conditions may not be effective for motion sickness. For example, metoclopramide and prochlorperazine, although widely used for nausea, are ineffective for motion-sickness prevention and treatment. This is due to the physiology of the CNS vomiting centre and its inputs from the chemoreceptor trigger zone versus the inner ear. Sedating anti-histamine medications such as promethazine work quite well for motion sickness, although they can cause significant drowsiness.

Ginger root is commonly thought to be an effective anti-emetic, but it is ineffective in treating motion sickness.

The World Anti-Doping Agency (WADA) determined that non therapeutic form of genetic manipulation for enhancement of athletic performance is not allowed in sport. The WADA code implemented guidelines to determine if said technology should be prohibited in sport. If two of the three conditions are met, then the technology is prohibited in sport; harmful to one's health, performance enhancing, and/or against the "spirit of sport". The high risks associated with gene therapy can be outweighed by the potential save the lives of individuals with diseases. According to Alain Fischer, who was involved in clinical trials of gene therapy in children with severe combined immunodeficiency, "Only people who are dying would have reasonable grounds for using it. Using gene therapy for doping is ethically unacceptable and scientifically stupid." As seen with past cases, including the steroid tetrahydrogestrinone THG, athletes may choose to incorporate risky genetic technologies into their training regimes.

The mainstream perspective is that gene doping is dangerous and unethical, as is any application of a therapeutic intervention for non-therapeutic or enhancing purposes, and that it compromises the ethical foundation of medicine and the spirit of sport. Others, who support human enhancement on broader grounds, or who see a false dichotomy between "natural" and "artificial" or a denial of the role of technology in improving athletic performance, do not oppose or support gene doping.

What follows is a list of all the athletes that have tested positive for a banned substance either during or before an Asian Games in which they competed. Any medals listed were revoked.

A lallation (also called cambia-letras or troca-letra, "letter changer", in Latin American countries) is an imperfect enunciation of the letter "L", in which it sounds like "R" (or vice versa), as frequently found in infantile speech.

The speech pattern has been particularly associated with the use of the Portuguese, Spanish and English languages by Chinese, Korean, and Japanese people. The use of lallation has thus been a common feature of Western stereotypes of East Asian people. It is also common among English-speakers in parts of East Africa.

Since the introduction of doping tests in 1964, many cyclists were caught in the Tour de France. In recent years, 1996 Tour de France winner Bjarne Riis and points classification winner Erik Zabel, along with most of their Team Telekom team-mates, confessed to using erythropoietin (EPO). In 1997, former points classification winner Djamolidine Abdoujaparov was disqualified from the Tour de France for doping use. In 1998, the Festina affair had several main contenders removed from the race. In the next years, several riders were removed from the Tour de France for doping (see List of doping cases in cycling).

In addition, several riders were not allowed to start the previous Tour, including Jan Ullrich and Ivan Basso because of their involvement in the Operación Puerto doping case, a Spanish investigation against doctor Eufemiano Fuentes and a number of accomplices accused of administering prohibited doping products to approximately two hundred professional athletes, to enhance their performance.

After the completion of the 2006 Tour, winner Floyd Landis was found to have an elevated testosterone to epitestosterone ratio on a sample taken following Stage 17 of the race, and at the time of the 2007 Tour prologue. Since the results of an independent arbitration hearing were still pending Landis was prevented from defending his title. He was stripped of his 2006 Tour title in September 2007.

Video game addiction (VGA) is a hypothetical behavioral addiction characterized by excessive or compulsive use of computer games or video games, which interferes with a person's everyday life. Video game addiction may present itself as compulsive gaming, social isolation, mood swings, diminished imagination, and hyper-focus on in-game achievements, to the exclusion of other events in life.

In May 2013, the American Psychiatric Association (APA) proposed criteria for video game addiction in the 5th edition of the "Diagnostic and Statistical Manual of Mental Disorders", concluding that there was insufficient evidence to include it as an official mental disorder. However, proposed criteria for "Internet Gaming Disorder" were included in a section called "Conditions for Further Study".

While Internet gaming disorder is proposed as a disorder, it is still discussed how much this disorder is caused by the gaming activity itself, or whether it is to some extent an effect of other disorders. Contradictions in research examining video game addictiveness may reflect more general inconsistencies in video game research. For example, while some research has linked violent video games with increased aggressive behavior other research has failed to find evidence for such links.

In 1996, they traveled to Germany, trying to convince doctors there to separate them; the German doctors however declined to operate, saying that the risk of separation surgery would be too high for both of them.

In November 2002, after meeting Dr. Keith Goh, the Bijani sisters travelled to Singapore to undergo the controversial operation. Even though they were warned by the doctors that the surgery to separate them would still be very risky, the sisters were very determined. Their decision to go ahead with the operation caused an international media blitz.

After eight months in Singapore, doing extensive psychiatric and legal evaluations, they underwent surgery on July 6, 2003, under the care of a large team of international specialists at Raffles Hospital, composed of 28 surgeons (including neurosurgeon Ben Carson) and more than 100 support staff working in shifts. A specially-designed chair was required that allowed the operation to be performed with both sisters in a sitting position.

The attempt to separate the twins turned out to be very difficult, because their brains not only shared a major vein (the superior sagittal sinus), but had fused together. The separation was achieved on July 8, 2003, but it was announced then that the twins were in critical condition, both having lost a large volume of blood due to complications of the operation.

The separation stage of the surgery completed at 13:30 (Singapore time, UTC +8), but there was significant blood loss during the blood vessel repairing process, and Ladan died at around 14:30 on the operating table; her sister Laleh died about 90 minutes later. Their deaths were announced by the chairman of Raffles Hospital, Dr. Loo Choon Yong.

Because few clinical trials and no meta-analyses have been completed, research is still in the preliminary stages for excessive gaming treatment. The most effective treatments seem to be, as with other addictions and dependencies, a combination of psychopharmacology, psychotherapy and twelve-step programs.

Some countries, such as South Korea, China, the Netherlands, Canada, and the United States, have responded to the perceived threat of video game addiction by opening treatment centers.

The ideal ratio of the length of the miniskirt, the exposed portion of thigh, and the over-knee part of the socks is often considered to be 4:1:2.5, with a tolerance of 25%.

Zettai ryōiki fans classify it by visible bare skin area, that depends on height of the socks and length of the skirt. A zettai ryōiki is graded from grade E (too much leg is seen, the skirt is also too long) to grade A (short skirt, high socks, short exposed area).