A former Army physical training instructor has set a new world record for the longest distance covered on a treadmill in a week.

Mike Buss, 35, ran 517.25 miles, smashing the previous best of 468 miles set by fellow ex-soldier Lee Chamberlain.

He spent more than 20 hours a day on the treadmill at the Brunel Shopping Centre in Swindon, running between 3.7 miles and six miles an hour. He had only two hours of sleep every day and short breaks for food and a massage.

The challenge cost him two toenails and left him with aching legs and feet, but Mr Buss insists it has been a worthwhile effort.

He said: “I was always looking at hitting the 500 mark so to go 17 miles further is brilliant.”

Supporting him throughout were soldiers from the Gloucestershire-based 29 Regiment Royal Logistics Corps, who have served in Iraq and Afghanistan.

Funds raised through the feat will go to Help For Heroes, which assists injured British servicemen and their families. Mr Buss hopes he will have raised £100,000 for the charity by Christmas and £1million by 2014.

He added: “What kept me going was the guys from 29 Regiment who really motivated me and kept my mind off the pain.

“I wanted to use my abilities as an endurance athlete to raise as much money as possible.”