He's the world's oldest marathon runner, and, at the grand old age of 100, Fauja Singh is certainly showing no signs of slowing down.

The nimble-footed centenarian, who has completed seven marathons since turning 89, was the first to sign up for the 2012 Edinburgh race, the Daily Mail newspaper said on Friday.

The key, according to Singh, to conquering his daily 10-mile training regimen is eating plenty of ginger curry and drinking copious amounts of tea.

"If someone says I must stop running I ignore them -- invariably they're younger than me. The secret to a long and healthy life is to be stress-free.

"If there's something you can't change then why worry about it? Be grateful for everything you have, stay away from people who are negative, stay smiling and keep running," he was quoted as saying.

The Sikh from Punjab says he developed his love for running while working as a farmer in the state. But it was not until he moved to the UK, half a century later, that he took up the sport seriously.

With the help of his coach, Harminder Singh, he started challenging other pensioners to races and has now run five marathons in London, one in Toronto and one in New York.

Singh holds the world record for the men's over-90 category after completing the 2003 Toronto marathon in five hours and 40 minutes, the report said.

He now hopes to take part in the Edinburgh Marathon Festival 2012, 26.2-mile race, as part of a four-man relay team with an average age of 86.