As sure as pale tourists will flock to Copacabana Beach, some athletes at the Rio Games will cheat — and most likely, only a few will be caught.

That’s because drug testers are always a step behind drug users. Sadly, there is no "Star Trek"-style scanner that will analyze a cup of urine or vial of blood and tell you everything that is in it. To test for performance-enhancing drugs with 2016 technology, you have to know which drugs you want to find.

Here’s an old example of the problem: When drug testing first arrived at the Olympics in 1968, the only person caught was a Swedish modern pentathlete who downed two beers before the shooting portion and tested positive for excessive alcohol. At the same time, weightlifters and other athletes were almost certainly using anabolic steroids, but a reliable test wouldn't appear at the Olympics until 1976.

Drug testers nab one or two athletes for every 100 tests they perform each year, according to the World Anti-Doping Agency (WADA), which oversees drug-testing for most sports federations.

But when British researchers assured athletes of anonymity during a 2011 study at two major track competitions, they found that between one-third and one-half probably had used banned drugs.

Still, not all is sadness and steroids. New tests detect a greater array of substances, and refined versions of older tests are more sensitive than they were even four years ago. In additon, WADA has significantly beefed up its Athlete Biological Passport, a record of an athlete’s normal blood and urine chemistry, so that it is easier to spot anomalies.

Even though it is likely that just a fraction of cheaters test positive, more have been caught in the past decade than in all previous years. The data from those cases show some interesting things about who they are, what they took, and why.

Doping violations by year

Number of doping violations by year, according to the Anti-Doping Database, which is missing data from some countries that do not publicly disclose cases. WADA’s totals for 2013 and 2014, the only years for which it has numbers, are higher but show a similar trend.

– 600

– 500

– 400

– 300

– 200

– 100

– 0

1970

1980

1990

2000

2010

1960

Source: Anti-Doping Database

– 600

Doping violations by year

– 500

Number of doping violations by year, according to the Anti-Doping Database, which is missing data from some countries that do not publicly disclose cases. WADA’s totals for 2013 and 2014, the only years for which it has numbers, are higher but show a similar trend.

– 400

– 300

– 200

– 100

– 0

1970

1980

1990

2000

2010

1960

Source: Anti-Doping Database

The numbers in this piece refer to Summer Olympic sports because that's where the most doping has been detected. The Anti-Doping Database, a compilation by former sports journalist Trond Husoe of Norway, contains detailed information on more than 5,500 of these cases dating to 1968. His dataset is not comprehensive because some countries do not release detailed doping information. Also, we eliminated equestrian, because horse-doping is a different animal.

Who gets caught cheating?

Doping violations by sex in

Summer Olympic sports

Men

82%

Women

18%

Some of the dopers are individuals who rolled the dice, betting that they wouldn’t be tested, and lost. Usually only winners and random others are selected for testing at competitions, and out-of-competition testing is spotty in some sports and countries. Others were part of a training group, team or country that was found to have an organized doping system in place.

Still others messed up accidentally, taking a nutritional supplement or cold medicine without knowing what was in it, for instance. A few claim they were sabotaged. (WADA rules are clear: You are responsible for what ends up in your body no matter how it got there.)

Two-thirds of all doping violations in Olympic disciplines have come from three sports: track and field, weightlifting and cycling.

31%

Track and field

16%

Cycling

16%

Swimming

Weightlifting

Tennis

Rugby

Water

Polo

Soccer

Judo

Volleyball

Gym.

Canoe/

Kayak

Wrestling

Boxing

Other

Tri.

Wrestling

16%

Boxing

Weightlifting

31%

16%

Track

and field

Cycling

Basketball

Tri.

Handball

Rowing

Other

Water

Polo

Swimming

Water

Polo

16%

Wrestling

Swimming

C

y

c

l

i

n

g

Cycling

31%

Track and field

Boxing

Rowing

16%

Rugby

Other

Judo

W

e

i

g

h

t

l

i

f

t

i

n

g

Weightlifting

Tri-

athlon

There are some reasons for this.

The jury is out on whether drugs actually help performance in many sports, but in these three, the proof is conclusive: Doping works. (Anabolic steroids affect women particularly dramatically, although far more men have been caught.)

Track and cycling have a lot of prize money and endorsement dollars at stake, which may mean athletes have more incentive to skirt the rules and more cash to pay for illicit drugs and for help in using them.

But there are more nuanced reasons as well.

Track and field, which has by far the most drug offenses, is a high-profile sport with competitions all over the world. Its athletes are among the most numerous and the most tested (second only to soccer, according to 2014 data from WADA). Both track and cycling have reputations in need of repair, so governing bodies have been willing to put resources into getting rid of cheaters. More obscure sports may appear to be cleaner because their athletes are tested less rigorously.

In fact, track pales to weightlifting and even golf in the percentage of total tests that come out positive.

These sports had the highest percentage of doping in WADA’s 2014 data:

Positives

1.

8,806

Weightlifting

169

Total

tests

1.9%

 

2.

507

Golf

8

1.6%

3.

4,258

Boxing

55

1.3%

4.

5,154

Wrestling

60

1.2%

5.

2,034

Taekwondo

22

1.1%

6.

1%

25,830

Track and

Field

261

7.

1%

22,471

Cycling

221

8.

Judo

4,453

40

0.9%

9.

Shooting

2,616

23

0.9%

10.

Archery

898

7

0.8%

1.

2.

3.

4.

5.

Weightlifting

Golf

Boxing

Wrestling

Taekwondo

8,806

507

4,258

2,034

5,154

Total tests

Positives

55

8

60

169

22

1.9%

 

1.6%

1.3%

1.2%

1.1%

6.

7.

8.

9.

10.

Track and Field

Cycling

Judo

Shooting

Archery

25,830

22,471

4,453

2,616

898

261

7

221

40

23

1%

1%

0.9%

0.9%

0.8%

____

Note: Excludes equestrian events

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Weightlifting

Golf

Boxing

Wrestling

Taekwondo

Track and Field

Cycling

Judo

Shooting

Archery

8,806

25,830

507

4,258

2,034

22,471

4,453

2,616

5,154

898

Total tests

Positives

55

8

60

261

7

169

22

221

40

23

1.9%

 

1.6%

1.3%

1.2%

1.1%

1%

1%

0.9%

0.9%

0.8%

____

Note: Excludes equestrian events

Where do they come from?

Most violations since 1960

The distribution of violations in Summer Olympic sports since 1960 among the top 10 countries.

1. Russia

1960

2000

’15

2. United States

3. India

4. Italy

5. France

6. Britain

7. Spain

8. Australia

9. Sweden

10. Brazil

It’s not terribly surprising that Russia tops the list. It is a large country that competes in many sports, and it has had doping problems from the early days until now. At least 14 Russian athletes have been among the several dozen new positives to turn up this year in retested samples from the 2008 and 2012 Olympics. In addition, a whistleblower recently implicated the country's drug-testing officials in cover-ups that he said took place before and during the 2014 Sochi Olympics, and some Russian athletes are being banned from the Rio Games.

But countries with the most violations are not necessarily the dirtiest. Some countries have far more random testing than others, said University of Essex biochemist Chris Cooper, author of “Run, Swim, Throw, Cheat: The Science Behind Drugs in Sport.” So some places are finding more doping because they are looking more.

India, for instance, is not known as a doping powerhouse, yet it vaulted into the top three thanks to a spate of drug positives in the past decade. Cooper said this may indicate that as India has grown richer and more developed, it has become more interested in sports and is doing more testing.

India's Shailaja Pujari, who won gold in the 75kg snatch at the 2002 Commonwealth Games, tested positive for stanozolol in 2009. (Adam Pretty/Getty Images)

Most recent rankings

Countries with the largest share of doping violations in 2014.

0%

5%

10%

1. Russia

2. Italy

3. India

4. Belgium

5. France

6. Turkey

7. Australia

8. China

9. Brazil

10. S. Korea

China, on the other hand, despite an enormous population and a history of doping scandals, is just 12th all-time. Cooper thinks the Chinese may be doping less than they once did, but also said Chinese athletes rarely compete outside China, so they aren’t often subject to testing in other countries.

Finances play a role as well. Drug-testing is problematic in Jamaica because the country lacks resources, Cooper said. Kenya’s geography makes make surprise testing nearly impossible, as its distance runners tend to live far from labs.

The United States is the second-most-penalized country all-time, yet it is not among the top 10 in the 2014 list. Cooper said that might be because in the past two or three decades, the country has poured more resources into drug-testing and is aggressively trying to catch cheaters.

What do cheaters take?

Hundreds of substances are named specifically on WADA’s list of banned drugs, and thousands more are prohibited through phrases such as “and related substances.” That way, the rules cover drugs that may not have been detected or even invented yet.

Most, but not all, fall into these broad categories:

U.S. shot putter Randy Barnes won gold at the 1996 Olympics between a 1992 suspension for the steroid methyltestosterone and a lifetime ban for a steroid relative called androstenedione. (Lutz Bongarts/Getty Images)

Muscle-building steroids

More athletes in nearly every sport have been caught using anabolic steroids than any other type of drug. Plenty of weightlifters, swimmers and sprinters have used them to build muscle size and strength and to cut fat. But athletes in sports we don't think of as power sports, such as soccer and cycling, also take them to speed muscle recovery so they can train harder. Long-term use comes with serious health effects.

Jamaican 400-meter runner Dominique Blake was suspended after testing positive for the stimulant methylhexaneamine in 2012. (Aris Messinis/AFP/Getty Images)

Pick-me-up stimulants

Amphetamines and similar high-powered stimulants can increase alertness, improve reaction time, boost blood flow to muscles and cause euphoria or aggressiveness. They also may improve endurance and muscle strength. However, they also raise heart rate and interfere with heat regulation; several cyclists have died using stimulants during races. These drugs are banned only during competition, and athletes most often caught come from track, cycling, swimming, soccer and rugby.

Two-time Boston Marathon winner Rita Jeptoo of Kenya was banned for two years after she tested positive for EPO in September 2014. She is appealing the ban. (Timothy A. Clary/AFP/Getty Images)

Hormones such as EPO and drugs that modulate hormones

Some doping involves giving the body more of what it has already. The most notable is the hormone erythropoietin (EPO), which prompts the body to make more oxygen-carrying, endurance-increasing red blood cells. Another is human growth hormone, which athletes may take as a tougher-to-detect alternative to steroids — although scientific studies have questioned how well it works. Insulin, breast cancer drugs and fertility drugs are on the list as well; some may build muscle and others counteract some side effects of steroids.

Argentine wrestler Fernando Iglesias was banned for life after a 2011 test found furosemide, the diuretic that turns up most often in drug tests. (Bernardo De Niz/AP Photo)

Drugs that hide other drugs

Diuretics, or water pills, can help wrestlers and other weight-limited athletes drop pounds fast, and they can also dilute the concentration of other drugs in the urine, possibly enough to throw off a drug test. Drugs called plasma expanders attempt to do the same thing in the blood.

North Korean shooter Kim Jong-su tested positive for propranolol at the Beijing Olympics in 2008 and was stripped of two medals. (AP Photo/Charlie Riedel)

Calming beta blockers

These drugs lower blood pressure and heart rate and generally make people less jittery. They are banned in Olympic sports that require steady hands: archery, shooting (including modern pentathlon) and golf.

Australian swimmer Ryan Napoleon was suspended for three months in 2009 after a pharmacist mislabeled an inhaler that led him to use the wrong asthma medication.

Asthma drugs

Asthma drugs open breathing passages, but some also may build muscle and increase fat-burning. A 2015 Canadian study found that up to a quarter of Olympic-caliber swimmers have asthma diagnoses, and athletes who have asthma can use certain drugs without penalty if they get a "therapeutic use exemption" or TUE. Cyclists, swimmers and runners have most often been caught without TUEs.

The best-known Olympic marijuana case was from the 1998 Winter Games, when Canadian Ross Rebagliati won — then lost, then regained on appeal — the first-ever Olympic snowboarding medal. He later founded the medical marijuana company Ross' Gold.

Recreational drugs

This category covers drugs of addiction as well as marijuana. They are not generally considered to be performance-enhancing, and few Olympic-caliber athletes have been suspended for narcotics or opioids. Marijuana is another story — nearly all cases in this category involve marijuana — and nearly all the users are men.

Rugby player Filippo Giusti of Italy was suspended for a month in 2012 for taking prednisone.

Anti-inflammatory steroids

"Steroids" is in the name, but these are not the muscle-building kind — in fact, they can break down muscle. They are powerful anti-inflammatories and pain relievers. They can give users a quick jolt of adrenaline and may boost endurance a bit, but performance-enhancing value is not clear and suspensions for testing positive tend to be short.

Russian middle-distance runner Tatyana Tomashova was suspended in 2008 for substituting someone else's urine for her own to beat a drug test.

Other ways to break the rules

Not all doping sanctions involve failing tests. Other violations will get an athlete in hot water, including avoiding or tampering with a drug test and providing drugs to others. Certain methods are also banned, such as blood doping, in which an athlete stores bags of his own blood and intravenously puts it back in months later, boosting his red-cell count without drugs.

What comes next?

Just because some drug cheats may leave Rio with shiny new medals doesn’t mean they should mount them permanently in their living rooms.

As dozens of athletes from the Beijing and London Games are finding out, samples from the Olympics are stored for a long time — 10 years, currently. Those samples can be retested, and athletes punished, whenever a new detection method becomes available.

In addition to seeking evidence of new drugs, future anti-doping sleuths will look for gene doping — tweaking DNA to have greater endurance or stronger muscles, for instance — and other 21st-century ways of cheating. Maybe someone will even invent that "Star Trek" scanner.

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