This year's Great North Run will be the 40th time the half marathon is held.

Olympian Brendan Foster first had the idea for the run in 1979, inspired by a race in New Zealand, which took runners from the city of Auckland to the coast.

Initially, Brendan and his fellow founders expected around 1,000 runners to take part, but 11,000 signed up to the first Great North Run in 1981. The event has grown ever since, into a globally famous half-marathon which attracts elite distance runners and thousands upon thousands of amateurs from the North East, the UK and around the world every September. Around 1.2m have finished the Great North Run.

Nowadays, the Great North Run is about more than just the half marathon on Sunday September 13. This year's event weekend will stretch over three days, with runs on Friday, Saturday and Sunday, as part of changes announced at the Great North Run 40 event held in Newcastle on Tuesday.

For the first time, the Great North 5k race will take place on Friday September 12. Usually, the 5k is held on a Saturday, but the decision has been taken to move it to the Friday evening, to launch the weekend and free up the Saturday for the Junior and Mini Great North runs for children.

Catherine Foster, Great Run Company's brand and marketing director, explained: "We've moved 5k from Saturday morning to Friday night, to make that one a little bit bigger. It's going to act as a curtain raiser for the whole weekend and there's going to be a real party atmosphere. So that one's going to grow, hopefully to around 3,000 people taking part.

"We've played around with the timetable for Saturday, to fit more children into the junior events, so that's going to grow to be even bigger as well, with over 9,000 children taking part. That takes up the whole day. There are no huge changes to the format, but that's the whole day, so we're going to really celebrate the kids taking part on Saturday."

Catherine Foster, Sophie Mason, Paul Foster, Brendan Foster and Terry Deary launching the 40th Great North Run

A competition to design a Great North Run mascot will also be held. The winning design will be used by the Run's marketing team and come to life in the form of a costumed character who will be unveiled when the weekend starts.

Interest in this year's Great North Run has already been huge. The ballot opened on Monday January 6, there has been a 25% rise in applications compared to the same period last year.

New entertainment is planned to keep runners going through the course, as the organisers are aiming for a record amount of finishers in the main race.

Pictures from the Junior and Mini Great North Runs
Pictures from the Junior and Mini Great North Runs

Founder Brendan Foster explained that part of the secret to the Great North Run's success is the annual strive to improve every year and maintain its position as the world's biggest half marathon.

Speaking outside today's launch, the European Championships and Commonwealth Games gold medallist said: "People in that room, the team that organise the event, they need to be sitting down right now, saying, 'what does this look like in 10 years time and what does it look like in 20 years time?'

"Because one of the biggest challenges with the Great North Run is to stay top of the pile. If you look around us, Manchester United were top of the pile, Newcastle United were nearly top of the pile, lots of individual sports people were top of the pile. Unless you plan to be top of the pile, in the future, you won't be top of the pile."

This year, Horrible Histories author, screenwriter and Great North Run veteran Terry Dreary will release a feature length drama-documentary film, GNR 40, which will look back at the Great North Run and the way the event has remained consistent during four decades where the world around the run has changed greatly.

Entry for the 1.5km Mini Great North Run will open on February 25 and applications for the 4Km Junior Great North Run launch on February 18.

Head here to apply to enter Great North Run events