"This is definitely something special for me that I have not done before and I will definitely find it tough," Litt said.
"At the peak of my training, the most I would run is between 200 and 300 kilometres in a week and getting up to 300 is difficult.
"There are no guarantees I am going to finish but I will do everything I can to finish, even if I have to walk. My body is conditioned to running long distances."
The challenge is made harder by the terrain she will take on.
Today's run is relatively easier with the flat course around the Tauranga walkway from Chapel Street, then the Rotorua Redwoods tomorrow, Mount Maunganui beach on Sunday, over to Hamilton along the Waikato River trails on Monday before the final gruelling 12 hours running up and down Mauao on Tuesday.
"The most difficult part is running slower," she says. "Today around the Chapel St track I would usually run the 100k in 8.5 hours however if I do it at that speed I wouldn't be able to run the next day. So I need to do it in more like 12 hours.
"My coach Craig Kirkwood, who is a former marathon runner and based in Tauranga, has given me advice about running on the track and then the second day running on the trail hills."
Litt says she became involved with the charity through her previous work experience and she wanted to do something to help raise awareness and funds for Shine.
She welcomes supporters to run with her on each day's challenge beginning at 5am.
Go online and visit www.fundraiseonline.co.nz/Shannonleigh to make a donation and support a great cause.
