Australia's leading marathoner Lisa Weightman has added her name to the list of entries for the Perth City to Surf on August 29 after turning down an opportunity to compete in Sydney's big charity race as part of her preparation for the Commonwealth Games.

Weightman, who was pre-selected for New Delhi after last year's world championships where she posted a 2hr 30min. marathon, will be running the traditional 12km distance in Perth as part of the Sam Maxwell Management team.

She will be a chance to beat Liz Miller's record of 41min. 24sec., well outside her personal best for the distance of 39:49.

The 31-year-old Victorian collected her first major international marathon win in Nagano, Japan in April breaking through the magical 2hr 30min. barrier with a PB 2:28:48.

But despite her impressive credentials over the distance, she will not competing for the $20,000 first prize in the marathon in Perth to ensure she is at her best in India in October.

She said the Perth City to Surf had not been part of her plan for the year but an opportunity to race in a corporate team alongside her husband, Lachlan McArthur, persuaded her to abandon her plans for the Sydney City2Surf.

"It is too close to the Commonwealth Games to do another marathon after my win in Japan," Weightman said.

"It takes four to six weeks to recover if you are running a competitive pace and I wanted to make sure I give my body extensive time to recover.'

Reuben Kosgei of Kenya has also joined the City to Surf field.

The youngest ever Olympic champion in the 3000m steeplechase in Sydney in 2000 when he was 21, went on to win the world championship in the same event the following year in Edmonton, with a bronze at the Melbourne Commonwealth Games in 2006.