Jamaican sprint champion Usain Bolt has made a firm decision on his Olympic future after wavering since the summer of 2013.
"It'll definitely be my last Olympics," the 17-time Olympic and world championships gold medallist told German news agency SID of this summer's Games in Rio de Janeiro.
"It's going to be hard to go four more years for me, to keep the motivation that I want, especially if I accomplish what I want to in Rio."
In the past two Olympics, the 29-year-old Bolt has won six gold medals in the 100 metres, 200 and relays. He has 19 career medals, including 11 world championship gold and two silvers won as a 21-year-old in 2007.
Before he retires in the next four years, Bolt added, he wants to break the 19-second barrier in the 200 while planning to win three gold in Rio.
"That's my focus, that's what I want," he told SID. "And that's what I'm aiming for because that's my goal and that's my dream."
Bolt won the 100, 200 and 4x100 relay at the 2008 Beijing Olympics and 2012 Summer Games in London. Should Bolt sweep again in Rio, he would share the record of nine Olympic track and field titles with Paavo Nurmi and Carl Lewis.
He also won all three events at the world championships in 2009, 2013 and last August in Beijing and is the world-record holder in all three. At the 2011 worlds he won gold in the 200 and 4x100 but was disqualified for a false start in the 100.
Previously, Bolt has vowed to retire after the 2017 world championships in London.