A SELF-CONFESSED former couch potato is about to set off on a unique challenge - walking 711 miles in the back of a lorry.

Rory Coleman plans to walk from Newquay to Newcastle in 36 hours, piling up the steps on a treadmill in the back of an articulated lorry.

Mr Coleman will start the challenge on January 5 - the 10th anniversary of the day he changed his life.

Then weighing 15 stone, the 40-a-day smoker from Nottingham took up walking, then running and has now completed 480 marathons, walked across five of the world's deserts and has set nine Guinness Hall of Fame records for treadmill endurance feats. His latest feat of endurance is expected to end on the evening of January 6 when he arrives at the Millennium Bridge on Newcastle's Quayside.

The stunt has been organised by the Get Fit Foundation (GEFF), which hopes to encourage the public to walk off the Christmas pudding by exercising at least five times a week. The project aims to cut the UK's growing levels of obesity, which is estimated to cost 30,000 lives a year.

Mr Coleman said: "I know how difficult it is for people to get started and stay active - until ten years ago, I was the original 'couch potato'.

"Walking changed my life and I really believe that when our nation is rallied, we can achieve anything.

"So we are urging everyone to support us en route and learn how GEFF can motivate them to get up off the couch and start to take beneficial exercise."