Kylie's ultramarathon effort for kids

Some people hope to run one 42km marathon in their life - Kylie Williams is preparing for a gruelling 50km run each day for 20 days.

The WA Police detective hopes to raise $50,000 for the Australian Childhood Foundation to support children and families devastated by abuse, violence and neglect.

About 4000 cases of physical and sexual abuse and child neglect were reported to WA Police each year, Det-Sen. Const. Williams said.

She spent more than two years in the child abuse squad and said every case was distressing.

"I don't think many in the public realise what people can do to kids, particularly their own children," she said. "It was one of the most difficult but rewarding places I have worked.

"It is rewarding when you have the evidence to charge an offender, but you can't do much for the children, so I wanted to help an organisation that looks after victims."

After the 250km Marathon Des Sables in Morocco last year, Det-Sen. Const. Williams started planning something bigger and better to fundraise.

"I figure that 20 days of pain is nothing compared with what some children and their families suffer on a daily basis," she said.

Det-Sen. Const. Williams is holding a charity event at South Perth Community Centre on Friday. For details and to follow Det-Sen. Const. Williams, visit her Facebook page at www.facebook.com/pages/Running-Pink/334321733395915 .