Madam Deirdre Larkin breezes through Johannesburg's suburbs most mornings, her white hair buffeted by the wind as she runs her well-trodden 8km training course.

At 85, the retired concert pianistholds the world record time for the half marathon for her age group, reported the Daily Mail Online. Standing in front of a wall of some 500 medals recognising her athletic feats in her home, she said: "Before I turned 78, the last time I ran was in college, and I was really bad."

Madam Larkin, who moved to South Africa from Britain in 1970, started her running career in 2010 when her doctors told her that she was developing osteoporosis, South African online newspaper Randburg Sun reported.

In May, she was invited to compete in Switzerland, where she completed a half marathon in 2hr 5min, setting the world record for her age group, said the Daily Mail Online.

And despite soon turning 86 in September, Madam Larkin has no intention of slowing down. "I can imagine a life without running, but it is a kind of slow death," she said. "I am going to run as long as I can."