For a Parkes couple and some of their close friends and family, this is part of their training sessions.

Helen and Corey Rowbotham – along with Rebecca Rawsthorne, Douglas Hodges, Lisa and Michael Gould from Cookamidgera, and Phillipa Morgan (support crew) – will be walking 65 kilometres for cystic fibrosis this weekend.

They are taking part in Sydney's longest one-day walkathon, the 65K 4 65 Roses Walkathon on February 23 to help support Cystic Fibrosis Community Care and the Children's Hospital at Westmead.

It’s an annual fun walk and endurance event around Sydney's Iron Cove Bay held to raise funds for the fight against cystic fibrosis, a life threatening genetic condition affecting thousands of young Australians.

65K 4 65 Roses is named after the ultra-marathon distance of 65 kilometres, and uses the name 65 Roses - which is the nickname for cystic fibrosis.

“When we put the call out to friends and family to join our team and walk 65k for cystic fibrosis we did not expect anyone else to be this crazy,” Helen said.

“Now we are a fabulous team of eight.”

Helen said they've been considering the walkathon for a while but just never had the chance to do it, until now.

The walkathon is a seven kilometre circuit where participants can walk or run as many laps as they want.

For those doing the 65 kilometres they will begin at 2am and aim to finish at 5pm.

The local team consists of four people from Parkes, two from Cookamidgera, a friend from Sydney Stacey Walsh and Corey's sister Nicole Palmer from Newcastle, and a Parkes support person.

Helen said they also have family members in Broken Hill and Coffs Harbour walking from where they to support the cause.

And what's their motivation? Helen and Corey’s two sons, Callum (10) and Harry (7), who they have named their team after and who both have cystic fibrosis.

“Fortunately they have a milder form of the disease but still require daily nebulised medication and physiotherapy,” Helen said.

“Essentially they’re missing an essential protein which results in mucus in various parts of the body, becoming sick and sticky, so for our boys it really affects their lung function.

“For a lot of cystic fibrosis people it also affects their digestive system so we’re very lucky that it’s only affecting their lungs at this point.”

Helen said they have a daily regime, which can be rather challenging.

“They do chest physiotherapy every morning before they go to school and then in the afternoon they do nebulised medication,” she said.

“Neither of those can be missed so that’s a challenge in itself when you’ve got two boys who don’t always want to do that.

“CF people actually lose a lot of salt in their sweat so we do lots of salt replacement in all their food, their drinks, making sure they’re keeping up their fluids because they can get dehydrated very quickly.

“Then there’s the challenge of physical exercise...and also infection control, that’s the biggest part, keeping them well.

“But they’re amazing, they take it all in their stride."

Callum's and Harry's school, Holy Family Primary, rallied behind the cause last week, with students having a crazy hair day and raising $530 for the walk.

Principal Nick Baird donated iTunes gift cards for the best boy and best girl, as well as ice blocks for all the students.

The regular six or more hour walks to the Dish have been helping the team prepare for the event, their last session taking place on February 10.

“Getting there was fine,” Helen said.

“Probably the last 10-15 kilometres that was then we were realising the challenge that’s ahead of us doing 65.

“We’re just nursing the feet and then there’s the heat and water, all those challenges that come with an endurance walk.”

So far Team Harry and Callum has raised $4211.83, contributing to the $221,769 combined total everyone participating in the 65K 4 65 Roses Walkathon has raised.

They are reaching out to anyone in the Parkes community who may also like to support their cause.

People can donate by visiting their fundraising page on Everyday Hero https://65k2019.everydayhero.com/au/team-callum-and-harry.

“The more people who know about 65 K 4 65 Roses Walkathon, the greater the impact,” Helen said.

"It's (cystic fibrosis) a huge thing to just come to terms with, for Corey and I it was having two boys with a life-limiting illness and now we're at that stage of educating our boys and helping them understand it and work through the challenges at school and at home, it's hard sometimes."