Dinah Gould, who will be a centenarian by the time she walks a 300-metre leg, was one of 7,300 torchbearers named by organizers on Monday.
"I just hope I do a good job," she said, leaning against her walking stick.
Gould, who prefers to use Diana as her first name and remembers the 1948 London Games, put her fitness down to yoga and chocolate.
"I'm a chocoholic and good health is in my genes - my mother lived until she was 102," she explained.
The 99-year-old was wearing the official torch relay kit, mainly white with gold shards, which organizers described in a statement as "accenting the energy of the Olympic flame".
Seven hundred more torchbearers, including celebrities, are due to be announced at a later date with the relay starting on May 19 and travelling 8,000 miles around the country before the opening ceremony at the Olympic Stadium on July 27.
Also donning the kit at a school in east London was the youngest torchbearer, Dominic Macgowan, one of the 212 children who will be 12 at the time of the relay.
"I'm most nervous about falling over," said the keen footballer from Birmingham, central England.
Other torchbearers included a member of the reserve forces who was injured in Afghanistan in 2009, an IT analyst whose parents emigrated from Bangladesh to set up home and a new business where the Olympic Park now is and a girl who wants to coach soccer in the United States when she is older.
Among the thousands named are also youngsters from 20 countries, from Azerbaijan to Zambia, that are part of London 2012's International Inspiration program. They include Shariful, an 18-year-old community swimming instructor from flood-prone Bangladesh.
"I'm thrilled that young people from around the world will also get the chance to run with the Olympic Flame," said LOCOG chairman Sebastian Coe.
NOMINATION PROCESS
Organizers also named the streets where the torch will travel during its 70-day tour.
A large number of the torchbearers were put forward by family, friends and local communities through a public nomination process.
Each bearer will carry an individual version of the gold-colored triangular aluminium torch which has been likened to a large cheese-grater because of its meshed appearance.
It will be carried each day by 115 bearers on average, taking in the outer reaches of Scotland, Wales and Northern Ireland as well as the Irish capital Dublin.
Methods of transport will include boat, cable car, hot air balloon, bicycle, motorbike and horseback, as well as foot.
The journey will pass many monuments and historic venues and be protected by specially selected police teams.
Police have said that if there are any demonstrations they will probably come more from attention seekers than from violent protesters, who marred the torch relay four years ago before the Beijing Games.
After having its flame ignited by the sun's rays at Ancient Olympia, the torch relay will begin at Land's End, the most southwesterly point of England.
(Editing by Tony Jimenez)