- CNN Sport takes a look at Brazil's main Olympic hopes
- Amid environmental & political turmoil, athletes can bring welcome relief
Rio de Janeiro (CNN)They could be heroes.
As an Olympics facing phenomenal off-the-field strain dawns in Brazil, the country's athletes are preparing to block out national demons.
Water issues, Zika virus, politics, security and the economy are not theirs to deal with. Theirs is a simple mission: win.
Competing for the host nation at an Olympics is a unique, emotive sporting thrill, but the privilege comes with the potential for crushing pressure.
CNN has selected a handful of Brazilian Olympians primed for sporting immortality on the biggest stage of their lives when the Rio Games begin -- if they hold their nerve.
No Brazilian on the Rio team has more big-game experience than Neymar. With Barcelona, the 24-year-old striker has won La Liga and the Champions League; for his national side, he is already among Brazil's highest scorers in history having poached 46 goals in 70 games.
Brazilians worship football, but no Brazil team has ever brought home the Olympic title. Three times the team has reached the final; three times, the players took home silver medals -- most recently losing 2-1 to Mexico in the gold-medal game at London 2012.
Brazil is widely expected to make short work of Iraq, Denmark and South Africa in Rio's group stage, with Neymar easily the biggest name in a side largely comprising under-23 players under International Olympic Committee rules. Germany, Argentina and Portugal could stand in Brazil's way, while Mexico returns to defend its title.
If the men fail, Brazil will look to its women -- also deprived of gold so far, having twice finished as Olympic silver medalists. However, having been knocked out in London 2012's last eight and disappointed at last year's World Cup, a marked improvement on home soil is needed.
When Rio was chosen as the 2016 host city, this sport instantly became a star attraction: Brazil loves beach volleyball, the Copacabana venue is iconic and the hosts are hot favourites.
Two Brazilian pairs stand a strong chance of taking the women's title. Larissa Franca and Talita Antunes are top of the Olympic rankings, but compatriots Barbara Seixas de Freitas and Agatha Bednarczuk are last year's world champions.
Brazil also boasts world champions in the men's event, in Alison Cerutti and Bruno Schmidt. They are joined by world bronze medalists Pedro Solberg and Evandro Goncalves.
With games throughout each day and four host-nation teams taking part, beach volleyball is guaranteed to hold the attention of home fans for hours and hours of airtime.
However, success in the women's event could depend on how the United States fares. Kerri Walsh Jennings, winner of the last three Olympic women's titles, is a star of the American team for Rio -- she enters the Games with a new partner in April Ross, and the two are the highest-ranked team in the world behind the Brazilians.
Robert Scheidt has won a medal for Brazil at each of his five Olympics so far.
The sailor, now 43, took his first gold medal at the Atlanta 1996 Games in the Laser class. He won another Laser gold in 2004 and most recently took bronze in the Star class at London 2012.
Scheidt's ability to reach the podium every time has made him one of Brazil's best-known Olympians, but he has already admitted to feeling the pressure of "huge expectations" this time around.
Moreover, Scheidt's sport has been buffeted by one of Rio's longest-running scandals in the saga of polluted Guanabara Bay. However, Scheidt has played down fears about the conditions -- noting lightheartedly that at Sydney 2000, athletes were worried about shark attacks.
His sixth Olympics, in Rio, is expected to be his last. With Star class having been dropped from the Olympic sailing schedule, Scheidt -- a third-generation Brazilian whose family originates in Germany -- will return to the Laser for his home Games, hoping to emulate his own success 20 years ago.
Brazil has only won one gymnastics medal in Olympic history, and that came courtesy of Arthur Zanetti at London 2012.
Then 22 years old, Zanetti triumphed on the rings -- one of the most demanding and impressive gymnastics events, involving contortions and displays of strength while suspended by the arms from rings above the floor.
In the intervening four years, Zanetti has added another world title and a world silver medal in his specialist event. He has also seen one of his trademark moves on the rings named after him and added to the Code of Points used by judges to determine athletes' scores.
One of the biggest dangers to the defending champion on home soil will be Eleftherios Petrounias of Greece. Petrounias, 25, has surged into world-beating form over the past year -- taking the 2015 and 2016 European rings titles, along with last year's world gold medal.
Brazil's judo team could produce two or three Olympic titles if the hosts get a little luck, with Mayra Aguiar arguably top of that list.
Aguiar started her career fighting the likes of Ronda Rousey, the former judoka turned MMA superstar, as a young teenager. Since then she has risen through the ranks to claim a bronze medal at London 2012 and the women's -78kg world title two years later.
Turning 25 just before the Rio Games begin, Aguiar says she's confident she now has the mental strength necessary to outwit her rivals in front of a home crowd.
But if she slips up, Brazil can look to a number of other contenders. Chief among them is Sarah Menezes, a surprise Olympic champion in the -48kg category at London 2012. Menezes, 26, fights on the first full day of the Rio Olympics and could be an early success story for the hosts.
Alternatively, 24-year-old Rafaela Silva has a shot at gold in the -57kg event having become Brazil's first judo world champion three years ago.
Brazil could come away from the Olympic tennis tournament with men's doubles gold -- but to do it, they will have to surpass some impressive pairings.
The doubles entry list includes the likes of Gael Monfils and Jo-Wilfried Tsonga for France, French Open doubles champion Marc Lopez alongside Rafael Nadal for Spain, and British entrants Andy Murray and Jamie Murray.
But Brazil has an exciting duo in Bruno Soares and Marcelo Melo.
Soares, 34, teamed up with Jamie Murray to win the Australian Open men's doubles title earlier this year -- while breezing to the mixed doubles title that same week. Melo, 32, was last year's French Open doubles champion and is routinely ranked first in the world for doubles tennis.
The two played together at London 2012 and reached the quarter-finals. Despite the high standard of opposition in Rio, they are tipped to do better with home court advantage.
Track and field is not a traditional source of Olympic titles for Brazil. Just one athlete, long jumper Maurren Maggi, has won Olympic athletics gold for the country this century. Fabiana Murer hopes to be the second.
Murer, 35, set a new Brazilian record in the pole vault during national trials for this year's Olympics and was the 2015 world silver medalist behind Cuba's Yarisley Silva.
Now, she plans to bow out of athletics with a medal-winning performance at her home Olympics -- telling reporters, "I always wanted to retire at my peak."
At Beijing 2008, officials misplaced Murer's belongings and she had to borrow equipment to compete. In 2012, she failed to reach the final. This could, at last, be her year.
Ana Marcela Cunha
April brought staggering news for the world of swimming: Cesar Cielo, the Brazilian superstar of the pool, would miss his home Olympics after underperforming in national trials.
Rio 2016 without the 29-year-old, a three-time Olympic medalist, had seemed unthinkable. Without his name on the start list, Brazil's hopes in the pool appear considerably weakened.
However, outside the pool -- in the open water -- Brazilians could still be set to shine.
Ana Marcela Cunha, a 24-year-old who reached the podium in the last two 10km swimming world championships, is considered a good bet for bronze at least in the women's marathon swim.
Last December, Brazil's Olympic committee named her its athlete of the year. The trick will be converting her dominance over even longer distances -- she is the 25km world champion -- into a medal over the comparatively breezy 10km.
Isaquias Queiroz has a remarkable story to go with his remarkable ability.
A three-time world champion in sprint canoeing, Queiroz is known for losing a kidney as a 10-year-old when he fell out of a tree while reportedly trying to catch a snake.
In other interviews, he has claimed he suffered severe burns when a pot of boiling water fell on him as a three-year-old, alleges he was briefly kidnapped at the age of five, and says he once overturned his car while driving to the airport but emerged unscathed.
For all that apparent misfortune, Queiroz has gone on to multiple world medals. However, while his preferred distance is 500m, the only Olympic events on offer are the 200m and 1,000m. The 22-year-old will try both, and will also team up with Erlon Silva for the two-man 1,000m discipline.
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