World champion and middle distance runner David Rudisha of Kenya will be seeking a strong start at the Shanghai Diamond League on May 13.

Rudisha leads a horde of other elite runners, who will be making their maiden show in the 2017 season, with the hope that their first step off the blocks will be strong enough to push them through to the London World Championships in August.

Rudisha said his purpose in Shanghai will not be winning, but what challenge his body will face as he throws down the gauntlet in defence of the world title in three months' time.

"It's not the triumph but the struggle that matters. How you train, your focus and target are crucial and that is what interests me. I want to do well in Shanghai, they have great fans in China," Rudisha said on Monday from Eldoret.

Indeed over four years ago, Rudisha clearly remembers that he injured his knee while training in New York and was forced to forfeit his title defence at the 2013 Moscow World Championships.

He endured a knee surgery and sat out for 12 months without competitive action. His return in late 2014 showed a man who was a pale shadow of the great champion.

A haunted figure as he struggled that season with three race defeats, one of which he finished last of the pack.

But he has slowly built his strength, changing his running tactics to win both in Beijing 2015 World Championships and in Rio Olympics.

"I'm really happy with my progress. The win in Beijing meant a lot to me. I went to China not in the best of fitness. I wasn't at the top of the world, I wasn't the favourite. I was an underdog. That worked on my side as I had little pressure. People were not focusing on me but the other guys. I sneaked in without a lot of pressure," he said. 

"In Rio, I made history, established myself as a true legend winning my second gold in Olympics. Now I want to go on until 2020 Games. That journey starts in Shanghai," he added.

Rudisha is one of four Beijing 2015 champions who will be looking for some early pointers just three months ahead of his world title defence.

The 800m world record holder made his Shanghai Diamond League debut in May 2016 and went on to retain the Olympic title in Rio in some style.

Rudisha leads compatriots Kipyegon Bett, Ferguson Rotich, Robert Biwott and Alfred Kipketer in the quest for points against Poland's duo of Adam Kszczot and Marcin Lewandowski while Zhang Dashan is the top runner from China.