Mellouli aiming to bow out with a splash

Oussama Mellouli, Tunisia's most decorated athlete, will go to the Olympics for the fifth time in Rio de Janeiro, capping a roller coaster swimming career that has included gold medals and a drug ban.

A two-time Olympic champion and the first African male swimmer to win gold at the Games, Mellouli, 32, said he is "calm" and "optimistic" that he can win one last medal.

"With the Olympics, I'm going to something I know well. For the young ones, it will be different," he said on the weekend.