News Michael Phelps The most decorated Olympian in history has pledged to hang up his swimming trunks after the Rio 2016 Olympic Games Phelps has already retired once - quitting the pool after London 2012, where he collected a record-breaking 22nd medal (including his 18th gold)  Last year, however, the 31-year-old American reconsidered and announced that he was making an Olympic comeback   He will compete in four events at Rio 2016 - the 100m and 200m butterfly, 100m freestyle and 200m individual medley - and will aim to end his career with a flourish Again Ye Shiwen The Chinese swimmer was just 16 when she surged to a double gold at London 2012 She set a world record with a breathtaking performance in the 400m individual medley and an Olympic record in the 200m individual medley, where she roared back from third place to first on the last lap Yet as Ye prepares to defend her titles four years later, the 20-year-old has said that Rio 2016 will be her last Olympic Games  Ye Shiwen's last Games will be at Rio 2016 (Getty Images/Lintao Zhang) Bryan brothers The 38-year-old identical twins are a doubles tennis phenomenon, having amassed 43 Grand Slam titles between them, along with a Davis Cup victory for the USA and Olympic gold at London 2012 Mike and Bob declared back in 2013 that Rio 2016 would mark the end of their glittering careers, but there are signs they may be wavering The brothers recently said they may continue for "one or two years" after defending their gold medal in Brazil, but either way they are unlikely be seen at another Olympics Robert Scheidt Brazil’s most successful Olympian – with two gold, two silvers and one bronze medal in sailing – the 43-year-old has pledged to make Rio 2016 his last Olympic Games Adding another medal in his home waters of Guanabara Bay would be the perfect end to a stellar career for the man from Sao Paulo At the top of his game, Robert Scheidt will retire in his home country (Getty Images/Matthew Stockman) Manu Ginobili Rio 2016 marks the end of an era for Argentine basketball, with 38-year-old Ginobili one of several members of a "golden generation" set to bow out of Olympic competition The shooting guard has a statue erected in his honour in Buenos Aires for his achievements, which include the gold medal at Athens 2004 - the only time the USA has been denied the title in the NBA era Rio 2016 is also likely to be the Olympic swan song for other stars of the 2004 side including Andres Nocioni, Luis Scola and Carlos Delfino Abhinav Bindra The 33-year-old Sikh shooter made more than a billion Indians happy when he claimed the 10m air rifle title at Beijing 2008 - the first and only individual gold medal won by an Indian athlete At 33, Bindra has vowed to call it quits after Rio 2016, where he will be India's flag bearer at the opening ceremony Carrying the hopes of 1 2 billion: India to send largest ever Olympic team to Rio 2016 Usain Bolt Jamaica's sprint superstar is targeting an unprecedented ‘triple triple’ in Rio, where he will attempt to defend the 100m, 200m 4x100m relay titles he won at the Beijing 2008 Games and retained at London 2012 If he does it, it would be a nice way to celebrate his 30th birthday on the day of the closing ceremony Bolt has shrugged off injury concerns ahead of the Games but recently said he intends to retire from athletics after Rio 2016 Serena Williams The 34-year-old American tennis legend is tied with Steffi Graf on 22 Grand Slam titles and has shown no signs of slowing down, holding the work no 1 ranking for 180 consecutive weeks and counting Serena Williams is in a rich vein of form going into her final Olympics (Getty Images/Bradley Kanaris) Serena is also the joint top Olympic gold medallist – she has four, along with her sister Venus – and she will defend the women’s singles title at Rio 2016, then look towards retirement   Sir Bradley Wiggins The 35-year-old cyclist, British Knight of the Realm and dedicated mod has won four Olympic gold medals, plus one silver and two bronzes After starting in the velodrome, Wiggins mastered the road, and now plans to return to the track for Rio 2016 If he wins an eighth medal, he will become the most decorated British Olympian of all time, having already become the first British man to win the Tour de France Sir Bradley Wiggins aiming to be crowned King of Great Britain at Rio 2016 Games Tamika Catchings Catchings, 37, has stood atop the podium at the last three Olympic Games as part of the all-conquering USA women’s basketball team The WNBA star has confirmed that she plans to retire after going for a fourth gold at Rio 2016 Tamika Catchings has her eye on another gold medal  (Getty Images/USOC/Todd Warshaw) Jo Pavey The 42-year-old Briton will make history at Rio 2016 when she becomes the first woman to compete for Team GB in five Olympic Games   She became the oldest female European champion in history when she won 10,000m gold at the 2014 European Championships in Zürich (10 months after giving birth to her second child) and will aim to repeat the feat in Brazil next month Jo Pavey poses with her European Gold medal (Getty Images/Dean Mouhtaropoulos) Earlier this year, a chest infecttion meant Pavey missed out on automatic qualification at the national trials but team leader Neil Black named her in the 80-strong track squad after she achieved the 10,000m qualifying time at the European Championships in Amsterdam in early July Federica Pellegrini Despite being only 27, the Italian swimmer has confirmed she will retreat from the pool after Rio 2016 - her fourth Games - to focus on her family life Pellegrini's gold medal in the 200m freestyle at Beijing 2008 made her first female Olympic champion from her country Lin Dan Considered by many the best singles badminton player of all time, 'Super Dan' became the first Olympic champion to successfully defend his title when he beat Malaysia’s Lee Chong Wei in an epic London 2012 final Despite rumours he was set to retire, the 32 year-old will go for a third straight gold in Rio Lin Dan of China will bow out of Olympic competition in Rio (Getty Images/Michael Regan)