Jamaican sprint star Usain Bolt has revealed that he is returning to Borussia Dortmund to do three weeks of training at the club.The fastest man on the planet spent two days with Dortmund last month but the 31-year-old now says he has plans to come back for an extended stay in the near future.

“For me, it’s a big deal,” Bolt the Herald Sun newspaper in Australia, where he is attending the Commonwealth Games as a spectator.

“Everyone feels like I’m just kidding around – [that] I’m joking. But I’m serious. I’m actually going back to Dortmund in a couple of weeks to work with them for three more weeks just to assess myself at a better level – to see what level I’m at or what I need to do, or if I can.

“So that’s something I’m focused on doing and I’m looking forward to the challenge because that’s what I want. I want a new challenge in life and that’s my focus.”

The eight-time Olympic gold medallist caught the eye with a well-taken header during his first spell at Dortmund. Bolt gave himself “a seven out of ten” for his performance, but has now said that his knowledge of the game had surprised people at the club.

“The first trial that I went to, they were very impressed,” he said.

“They didn’t expect me to know so much and understand the game. So it’s all about just improving right now. I personally think I can do it, and because I’m a hard worker. I’m determined – I know I can do it.”