MONACO • Usain Bolt has warned that the younger generation of sprinters are "too quiet" and overpaid, and must change if they are to fill the void that his retirement will leave.

The Jamaican, 30, the triple Olympic champion and world record holder in the 100m and 200m, revealed that he had advised Andre de Grasse to be more extroverted on the track. De Grasse also won three sprint medals at the Rio de Janeiro Olympics and the 22-year-old Canadian is widely seen as his most likely heir.

"I've said to a few athletes that I know personally, 'You guys need to show your personality, not just performance. Listen to me, I'm not trying to say you should try and do weird things, but people want to see personality and something different,'" Bolt said. "Hopefully they'll trust me and try to change."

De Grasse won silver behind Bolt in the 200m in Rio and footage of the pair exchanging grins in the home straight during the semi-final was widely shared.

Bolt, who will retire after the world championships in London this year, said he had singled out his young rival to give him advice.

He said: "I said to de Grasse last season, 'Listen to me, yes you're doing well, but you guys are too quiet. Look at the attention you got because we were having fun.' People were like, 'De Grasse is so cool'. "

With the world of athletics wondering who will take Bolt's place after he retires, he also cast doubt on the hunger of his potential successors.

"When I started track and field you didn't get paid a lot when you just came out of high school," he said. "Now when you have young talent, they get paid so early that a lot of them just lose their way real quick. If de Grasse can focus, or the other talents can focus, there is going to be great competition in years to come. But I've seen it so much, where the young kids start getting paid and they just drop out of the scene. It's all about who wants it."

However, he predicted that his 100m world record of 9.58sec, set at the 2009 world championships, would be broken within two decades.

"I think, just looking at the crop (of young sprinters) right now, I probably have 10, 15 years," he said.

Speaking before the Laureus World Sports Awards in Monaco, Bolt admitted that it had been hard to have to hand back one of his nine Olympic gold medals last month after Nesta Carter, one of his team-mates in the 4x100m relay in Beijing in 2008, retrospectively tested positive for a banned substance.

"It was sad, but I've learnt over the years that everything happens for a reason," he said. "I just have to deal with it."

But he said that he had no misgivings about his decision to end his career in August. "I think it's time to walk away," he said. "I never let track and field imprison me, but it does limit me from doing a lot of things that I would like to do."

THE TIMES, LONDON, REUTERS