Cameron van der Burgh has got his mojo back.

After a disappointing 2014, the Olympic 100m breaststroke champion said he was enjoying the sport so much he's thinking of going until the 2020 Games in Tokyo.

"I feel rejuvenated," Van der Burgh, 26, said in an interview yesterday.

"I really feel like I'm enjoying swimming a lot. Initially I thought I might retire after 2016 [the Rio Olympics], but I'm enjoying it so much ... I feel like comfortably I could go on to 2020."

Van der Burgh was his bubbly self again - a welcome change after the desperate face he presented at the Commonwealth Games in Glasgow where he was dethroned in the 100m by Englishman Adam Peaty.

"Last year was a tough year for me," he admitted, saying he was hindered by an injury to his left shoulder.

Plus he had lost his mojo.

"Unfortunately my shoulder really hampered my performance. It developed just before Commonwealth Games."

The mental problem was feeling no excitement before races.

But Van der Burgh spoke to his sports psychologist and by the time he went to the world short-course championships, he had that old feeling again.

"It was lovely to get over that. It was a year of learning," he said.

Van der Burgh will return to competition in Durban next weekend at the second Grand Prix gala, where he intends competing in the 100m breaststroke and all four 50m sprints - even backstroke, his worst stroke.

The world championships in Kazan, Russia in August will present him with an opportunity to renew his rivalry with Peaty.