Just so that we can get the record straight, Sir Christopher Chataway is sitting in his London flat running through his life in television and politics. "Yes, I was the first presenter on News at 10," he says. "It was 1955, the start of commercial television. Robin Day and I were the two newscasters and I did the news on the first day. Then I went over to the BBC and worked as a reporter on Panorama for four years.
"Then I went into politics. Under Harold Macmillan and Alec Douglas-Home I was junior Education minister, and then under Edward Heath I was Minister of Post and Telecommunications and Industry Minister. Then I left and worked in the City for 16 years and became chairman of the Civil Aviation Authority. That, in a nutshell, is my curriculum vitae... Never made up my mind what I wanted to do."
That is difficult to believe of this remarkable Renaissance man, who, four months short of his 80th birthday, remains as lean, sprightly and inspirational a figure as he was when he was one of the biggest stars of British sport. For that nutshell summary did not include the fact that Chris Chataway was such a sporting sensation in these shores that he was voted the very first BBC Sports Personality of the Year. That was in 1954, the year he paced Roger Bannister to the first sub-four-minute mile and smashed the world 5,000m record at the old White City Stadium in a duel with the Russian Vladimir Kuts that is regarded as one of the all-time epics of track and field.
On Sunday morning the 79-year-old will be one of 54,000 folk treading the road from Newcastle to South Shields in the 30th Bupa Great North Run. Accompanied by Derek Hull of Claremont Road Runners, whose "encouraging, very professional" pacing Sir Chris has greatly appreciated on his four previous appearances in the world's biggest half-marathon, he will be running the 13.1 miles against the clock.
His target is to run 1hr 52min and beat 80 per cent of the field in his 80th year. "If I manage to do that then I'll feel that 80 is not such a ghastly dead-end place to be," he says, chuckling.
Sir Chris was 73 when he made his Great North Run debut in 2004. He had been persuaded to take on the challenge by Brendan Foster, the founder of the Tyneside race, while the pair sat together at the 50th Sports Personality of the Year show. Sir Chris retired from the track at the age of 25 and did not start running regularly again until he was in his 50s, finding a new lease of life in a mass-participation, long-distance race and a joy in the act of running that was beyond him in his world-record-breaking heyday.
"It was immensely exciting, and absolutely thrilling to find that you were really good at something," he says, reflecting on an international track career in which he also won the Commonwealth three-miles title. "But did I enjoy my running back then? Well, er... a bit.
"It was so painful, because the sort of training we did one realises now was totally inadequate. I never ran more than 25 miles in a week. I smoked too. So the only way in which you could do well in major races was by pushing yourself extremely hard. In my old age I don't do that. I'm there to enjoy it.
"I sometimes think that running, which was a sort of tormentor in my youth, has returned to be a friendly codger in my old age – that what was Joe Stalin has turned into Dixon of Dock Green."
It is fair to say that most of the nation was captivated by Sir Chris's titanic battle with the supposedly invincible Kuts in the London vs Moscow match in October 1954, when he snatched a dramatic victory in 13min 51.6sec, a world record time. Fifty-six years on, he will be lining up on Sunday in a field that includes another former holder of the record, Haile Gebrselassie.
"That's a connection I don't mind having, I must say," Sir Chris says. "Haile is an amazing chap, and so unspoiled. I have enormous admiration for him."
The pair have met. Gebrselassie invited Sir Chris and his son Adam for lunch when they were in Ethiopia three years ago, planning the venture that is the main motivation for both Chataways running on Sunday.
Vicky's Water Project (www. vickyswaterproject.com) was set up after Adam's fiancée, Vicky Buchanan, was killed in a road accident while cycling to work in October 2006. Out of that tragedy came the triumph of a fresh water system supplying 20,000 Ethiopians in a collection of villages south of Addis Ababa, funded by the £600,000 raised by the project.
"The principal reason I'm actually running this year is because it's for us a celebration of the completion of Vicky's Water Project," Sir Chris reflects.
"They had the opening ceremony earlier this year and my wife and Adam and I were there. It was tremendous to see, because very often when you're running for some charity you can see what the need is but you don't often get the opportunity to see what the result is."
There will be live coverage of the 30th Bupa Great North Run on Sunday on BBC1 (9.30am-noon), on the Red Button (noon-1.40pm), and on BBC1 (1.40-2.25pm), with highlights on BBC2 (10.50-11.20pm)