"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," the world record holder in 100m and 200m told French news agency Agence France-Presse.
Last year Bolt several times mentioned that after 2017 London World Athletics Championships he would put an end to his track career. However this year in January the 6-time Olympic champion gave hopes to his fans by saying he might go until 2020 Tokyo Olympics.
This summer in Rio Olympics Bolt will try to three-peat in the 100 and 200 meters and 4x100m.