Two sisters from New Zealand, Sally Hewlett and Kim McVinnie, are suffering temperatures of 40C as they pedal up torturously steep hills in a bid to raise 4.000 USD for malnourished children in Vietnam.

The sisters are on the final leg of their 12-day cycling challenge from Hanoi to Ho Chi Minh City and plan to reach their destination by June 22.

Kim McVinnie, 44, signed up to cycle the 700 km from the north to the south of Vietnam after her 38 year old Auckland-based sister Sally Hewlett, who works at ChildFund New Zealand, twisted her arm and had to pull out.

She hadn't been on a bicycle for 25 years and on her first 2km outing six weeks ago, she thought she was going to die, but rode on through it. "I've never done anything like this before, so it's definitely taking me out of my comfort zone," said McVinnie.

Hewlett took on the challenge without any serious cycling training and rather than relying on her fitness, she thought of children she had met in Vietnam as a coordinator for ChildFund's Asia programme as she pedaled along and this motivated her to finish the ambitious trip.

McVinnie, who left her two children and husband at home to keep an eye on her sister, had never been to Vietnam before but managed to go for a couple of test runs before she left.

On average they have been riding about 80km a day, with a day's rest in between and using some public transport to help them reach their destination.

The money raised from the bike ride will go to ChildFund's Vietnam Appeal to reduce malnutrition among children by feeding them a mix of fortified nutrients called "sprinkles". The sisters have also been sampling some to help them complete their challenge.-VNA