'It makes me more hungry' - Wayde Van Niekerk eyes records after three-year injury setback

Van Niekerk romped to Olympic gold four years ago in a new world record time of 43.03 seconds, smashing the previous fastest time of 43.18 that had been set by American Michael Johnson in 1999.

But a serious knee injury sustained playing a charity touch rugby game in October 2017 left the South African's career in doubt, though he is now ready to return.

"Growth should be improving my times within the 42-second range. That's where my mind is at, that's where my heart is at," he told BBC Sport.

"That's just the competitor in me and for me to settle for anything less than that would mean I'm doing an injustice to myself and the team working for me. I have this deep desire to be out of reach. And after coming out of a period of somewhat suffering, it makes me more hungry."

The 28-year-old, who is the cousin of Springbok Rugby World Cup winner Cheslin Kolbe, admits he should never have accepted the invitation to play the charity event.

"My body was conditioned for running straight, not zig-zags. Later on you sit back and realise that the decision was obviously silly."

He admits that the injury he suffered while at the peak of his powers left him demoralised.

"The first two weeks were very difficult and showed signs of me climbing into a dark space. I had to start from scratch," he said.

"I had to tell myself from the beginning that I need to take responsibility for the decision I've made."