ATHLETICS: Jess Trengove has cemented her reputation as Australia's best female marathon runner far from home.

The 28-year-old's first five marathons have included a solid Olympic debut in London, a brilliant 11th-placed finish at the 2013 world titles in Moscow, bronze at last year's Glasgow Commonwealth Games and two hit-outs in Japan.

So when it came time to decide where best to lock in a qualifier for next year's Rio Olympics, Trengove decided on a change of tack, choosing Sunday's Melbourne marathon over established big-city events like Berlin or Chicago.

"I thought seriously about Berlin, it's high on the wish-list," Trengove told AAP.

"But for me it was really important to run a marathon in Australia - to be able to say to friends and family 'come and watch me and be a part of it'."

The Olympic qualifying standard of two hours and 42 minutes should prove no trouble for Trengove, who reckons she is in shape to better her PB of 2:30:12 set last year in Glasgow.

Presuming she locks in Olympic qualification on Sunday, Trengove and coach Adam Didyk will then have to decide whether she will contest another marathon between now and the Olympics in August.

But everything she does in the next 10 months will be geared towards Rio.

"When I made the team for London in 2012 I thought of it as my Olympic experience - to see what it was all about," she said.

"But I always thought if I made another Olympic team it wouldn't just be about going there to experience it.

"I will have more expectations on myself to raise the bar."

Another of Australia's very best female distance runners, Lisa Weightman, will contest the Melbourne half-marathon on Sunday, nine months after giving birth to son Pete.

Weightman is also targetting a berth on the Rio Olympic team and hopes to get the marathon qualifier in Houston in January.

The half-marathon field also includes Eloise Wellings, who recorded a commendable top-10 finish in the 5000m at August's world championships in Beijing.

AAP