That's 80 kilometres and more than 10 hours pounding the bitumen. Non-stop. Awake the whole time, naturally. Running.

"I enjoy it to the point where it's a little weird," she admits.

The 25-year-old personal trainer of Brookfield, in the US state of Wisconsin, ran her first ultra marathon in March and has plans to run two in October. "It's not generally recommended [to run two in a month] but after the ultra marathon in March I felt fine the next day," she said.

But her most challenging run will begin on the west coast of the US in March and won't end until September, when she reaches New York, on the shores of the Atlantic Ocean.

The inspiration for Ms Kumlien's 5000-kilometre trip is her mother Jill, who was diagnosed with multiple sclerosis 26 years ago.

"She has been a real inspiration to me my whole life," she said.

With the run, she hopes to raise awareness of MS and collect donations for MS research.

Another inspiration came in the form of 29-year-old Frankston South's Andrew Date.

Mr Date and Ms Kumlien met while working on a cruise ship in the Caribbean and an inspirational book she borrowed from him got her thinking big on how to lead a good life that would also benefit others.

MSRuntheUS was the result and the two are now a couple. Ms Kumlien is in Frankston visiting Mr Date and continuing her training.

On Sunday, she was at Frankston Oval to cheer him in Seaford reserves grand final win over Frankston YCW.

He will be a member of Ms Kumlien's support team next year and is holding a fund-raising golf day at Patterson River Country Club on Friday.

"It's a pretty big adventure," he said.

The couple, together with Ms Kumlien's family in the US, is busy planning for the run.

For more information visit msruntheus.com