Kenya and Ethiopia have set the bar high of the women's marathon at two hours, 17 minutes but this does not bother Mapaseka Makhanya ahead of her debut at the IAAF World Championships.

The London track and field global meeting will be the first time experience for the 32-year-old from Naledi, Soweto, who only entered the long distance fray just four years ago following her transition from the track to road.

She and Jenna Challenor will represent SA in the 42km race on Sunday afternoon.

Makhanya has not appeared in any of the classic distance (42km) events this year except for regular runs in shorter road races over the past few months.

"The shorter distances were part of my training for the marathon, especially with speedwork," she told Sowetan before her departure to London on Tuesday.

"If I had run a marathon earlier, I don't think I would have run at the [world] championships because you can only race so much [in the 42km]."

Some of the shorter races that the Olifantsfontein Athletics Club runner had used as her time-trial include three top 10 finishes in the Spar 10km Women's Challenge between April and June, as well as her second placing at the SA Half Marathon Championships in Port Elizabeth in June.

"I would really love to be in the top 20 [in London]. For me that's a realistic goal. And to do that I must go under 2:31 [her personal best time of 2:31:02 set in 2015]."

That will mark a massive personal achievement for her, seeing that she ran a 2:37:19 in her last marathon - the Shanghai Marathon in China - in October.

The time breached the IAAF entry standard of 2:45:00 but not Athletics SA's stringent qualifying mark of 2:28:48 - making her one of the few "B-standard" selections in the team.

However, for Makhanya making it to London has compensated for her last-minute withdrawal from the team prior to the 2015 World Championships in Beijing.