It's the biggest event for children and young people in the Leeds sporting calendar.
And this year, the Yorkshire Evening Post-backed Jane Tomlinson Arena Junior and Mini Run will be bigger and better than ever.
The capacity for this year's event – officially launched today – has been increased from 1,100 to 1,500 places and, thanks to its sponsor Arena, EVERY child can run for FREE.
Youngsters taking part in the event are simply encouraged to raise just a small amount of money for a charity of their own choosing.
Last year, many chose to donate to the Jane Tomlinson Appeal, with the charity spending the 10,000 raised on helping to refurbish a paediatric play area at Leeds General Infirmary, where Jane used to work.
The run, to be held this year on Sunday, May 8, is the third annual event of its kind, originally inspired by the late cancer campaigner and fundraiser who clocked up a series of incredible challenges, despite suffering from terminal cancer.
She launched the annual adult race, the Leeds 10K Run for All, before she died in September 2007.
But widower Mike said she always wanted to have a similar event specifically for children.
Mike, 49, from Rothwell, Leeds, said: "Jane really wanted us to be able to host a children's event and she would have loved to see the junior and mini run take off as it has.
"Last year's run was a fantastic success and to be able to refurbish a paediatric department really made the day worthwhile.
"We love being able to host this event because it is entirely free for children to take part – we hope as many youngsters as possible will take up the opportunity."
This year's junior and mini run will raise money to refurbish two children's wards – wards 48 and 48a – at Leeds General Infirmary.
Paul Napier, editor of the YEP, which is backing the event, said: "It was a great spectacle last year to see 1,100 children running through the streets of Leeds.
"To be able to open the event to another 400 youngsters is fantastic.
"They will have a great day and also be able to raise some money for a brilliant cause."
The Jane Tomlinson Arena Junior and Mini Run – thought to be the biggest free mass participation event in the UK – takes place on the same day as the Leeds Half Marathon and sets off from Millennium Square, Leeds city centre.
There are two courses for children of different ages: the Junior run is for nine to 14-year-olds and is 2.5km long; while the mini run is aimed at three to eight-year-olds and is 1.5km long.
For the mini run, there needs to be at least one adult per two children. The adults also run free.
Entries are now open to schools, families, organisations, groups and individuals.
* Go to www.runforall.com to register for the event.