The highly anticipated 89km down run from Pietermaritzburg to Durban kicks off at 5:30am on Sunday from the City Hall.
Wiersma is widely expected to be the first to cross the finish line and claim the R550,000 winner’s prize. After finishing second in his debut two years ago, he returned last year to win the race in just his second attempt.
He says he plans to run the best race he can and hopes that will be enough to secure another victory.
"For me, it doesn't really change anything, like I was saying in the press conference, I'm not running for anybody else's expectations. Two years ago, I came here and nobody knew me, last year I came here and everybody knew me. This year I come here and I'm a favourite in many people's eyes,” Wiersma said.
“So, to me, it doesn't change anything because every year I come back here, it's like I'm running the race for the first time like Gerda [Steyn] also said during her press conference.
“It's also a way of respecting your race, I would say and just every year you come back, not focusing on doing what is enough, what might be enough based on your experiences in the last two years.
“I'm just coming in there with a completely open mind, being the best version of myself that I can be. I've had that goal throughout the last few months of preparation and also especially going into this race. I just want to run the best possible race that I can and I'm gonna hope it's gonna be enough for the win."
The Netherlands-born runner told the national broadcaster that he is in the best shape of his life after spending three months at a training camp in Kenya.
"I spent most of the year in Kenya, I went through some difficulties there but especially during the second half of last year but I feel like I really got it right, now, coming back in March to really start my preparations for Comrades in Kenya,” he added.
“In that sense because it happened on time because I've been really into everything I'm doing, staying healthy, doing regular medical check-ups and just knowing what I have to do to prepare myself best for Comrades, I think I'm better prepared than ever."