At 9.00 am last Sunday morning around 35,000 pairs of trainers prepared to pound the capital's streets in the Flora London Marathon.

At the same time, millions of people across 150 countries turned on their televisions, settled back with a cup of coffee and remain glued to the screen for the next three or four hours.

Why do so many people choose to put themselves through 26 miles 385 yards of physical and mental hell? And why do we want to watch them do it?

The first London Marathon took place in 1981, the result of a pub conversation over a few pints of bitter and the experience of the late Chris Brasher who had just run the New York City Marathon.

Brasher, an athlete and sports journalist, asked himself if London could host such a race: "We have the course . . . but do we have the heart and hospitality to welcome the world?"

Today the scale and success of one of the country's most anticipated annual sporting events would give Brasher his answer. The London Marathon is a winning combination of spectacular setting and human drama.

The bobbing, multi-coloured ribbon of people weaves its way through some of London's most iconic sites and outstanding architecture. Greenwich, Canary Wharf and Docklands, the City, the River Thames, Tower Bridge, the Embankment, Parliament Square, Big Ben, Buckingham Palace and The Mall provide a suitably dramatic and beautiful backdrop to the stories of the thousands of individuals involved.

This year, 92,000 hopefuls applied for a starting place on Blackheath. We're all impressed by the elite runners and wheelchair athletes with their two hour sprints along the course, but let's face it, we're much more interested in the real people.

These are the people who've spent months abstaining from booze and cakes, fundraising for their special charity and punishing themselves in training - all whilst holding down their normal job and home life. Applicants this year included 83 taxi drivers, 2,148 teachers, 383 secretaries, 95 pharmacists, 97 film makers, 586 builders and 405 accountants.

The youngest individuals who took part in this year's race were Jonathan Smith and Siobhan Besford, both 18 years. The oldest were Buster Martin, aged 101 and Iva Barr, aged 80. Buster gained notoriety last year as a senior hero, for both refusing to take his 100th birthday off work and fending off a group of young attackers. He has since joined a band, The Zimmers, and become an agony uncle for lads' mag, FHM.

Runners from Great Britain and Northern Ireland always make up the majority of participants in the London Marathon, with around 50 other countries represented.

Many runners hope to break other records as well as their personal bests. The Guinness World Records for running the marathon dressed as Elvis, on stilts, whilst knitting a scarf or carrying a coal bag were all up for grabs last Sunday.

The marathon is all about the strength of the human spirit and our ability to triumph over adversity. That's why we are so touched by the stories of those running in honour of family or friends and the charities that have supported them.

We also love the men and women for whom one straightforward marathon just isn't enough: those who run five consecutive races or run the marathon course backwards in the early hours of the morning and then start with everyone else to run it again, forwards the second time; and those 25 Metropolitan Police Officers who run together in a chain.

Another of the highlights of the London Marathon is the sight of some of our celebrities slogging it out on the city streets. Floella Benjamin OBE and world-renowned chef Michel Roux have both run 10 London Marathons; James Cracknell, Olympic rower and celebrity chef Gordon Ramsey are both event regulars.

Unlike many other sporting events, there is a special relationship between the participants and spectators. The athletes and the crowd interact, working together to lift the spirits of ailing runners and urge them on to the finishing line. Veterans of the endurance race say there is nothing like hearing your name being shouted to inspire you.

Of 36,396 starters last year, 35,694 were inspired to finish. More than 34,000 runners finished this year. Completion times over the years range from two hours five minutes 15 seconds to seven days. And it seems that the marathon is addictive to both viewers and participants alike, with thousands applying year after year, despite vowing 'never again!' as they cross the finish line.

In addition to raising cash, increasing awareness of charitable causes and promoting running as a sport, the marathon is also responsible for boosting the British tourist industry. The London Marathon attracts runners from around the world and also showcases our capital city to a global television audience. Some London hotels run special marathon deals and many participants stay at Heathrow airport hotels.

Since 2006 the London event has been part of the World Marathon Majors, a series of races which includes the world's five biggest city marathons: Boston, London, Berlin, Chicago and New York City.

The 100th anniversary of the Olympic Marathon will be marked officially at the Beijing Olympics.