LONDON (Reuters) - When 6,204 people took part in the 1,000th parkrun in London's Bushy Park last month it was 6,191 more than set off in the inaugural event in 2004 and similar record turnouts are expected all over the world on Oct. 5 when the phenomenon marks its 20th birthday.
From those modest beginnings in the south-west of the capital, parkrun has grown at a scarcely believable rate, while largely retaining its most basic elements.
It is a free to enter 5km run that takes place every Saturday morning (there are also 2km junior parkruns on Sundays)and organised entirely by volunteers.
Everyone finishing is given a token with a barcode that, along with their personal barcode, is scanned after the run with the results emailed to the runners later in the day.
Fundamental to parkrun's ethos is that it is not aimed primarily at fast runners, though they are welcome and embrace it, but at the wider community, especially those who have not had physical exercise as part of their lives for a long time.
So, alongside enthusiasts vying to be "first finisher" (nobody is allowed to win), are runners of every size, shape and age, with dogs and buggies also welcome.
It is a matter of pride for parkrun that its average finishing time gets slower every year - an indication of more "less sporty" people getting involved, and each run has a "tail walker" to accompany the last runner, however long they take.
To say that it has proved popular might be the greatest understatement in the history of sport and public health.
FIRST EVENT
The original event for 13 friends was launched by Paul Sinton-Hewitt, who was inspired by the regular time trials he used to run in South Africa and was awarded a CBE 10 years ago for his services to grassroots sport and public health.
A trickle of expansion meant that within three years there were five more events, then known as UK Time Trials.
As the numbers grew into double figures and the events moved further from "keen runners" to community gatherings, the new "more representative" name of parkrun was adopted.
It reached 50 venues in 2010, the year when the junior events on Sundays were added.
On its 10th birthday, 1,705 parkrunners, including the original 13 and their five volunteer helpers, all took part in the Bushy parkrun on Oct. 4 2014, while regular Christmas Day and New Year's Day events are always hugely popular.
Then-CEO Tom Williams, who left the organisation this month after 13 years, proved prescient when he told Reuters at the time: "In 10 years we will look back and laugh at how small we were."
Those 472 venues have grown to over 2,500, in 23 countries, and the organisation has become a charity.
Heading into the 20th anniversary there have been more than 100 million finishes in parkrun and junior parkrun and almost six million different people have completed one.
Over 300,000 take part every week, with another 40,000 volunteering - some of the more than 900,000 different people who have helped put on an event.
Almost 2,000 GP surgeries around the world are twinned with a parkrun while events are held in 25 prisons and young offenders institutions, positively impacting the lives of more than 10,000 of those in custody.
POWERFUL FORCE
Looking back at the monster he created, Sinton-Hewitt describes it as "almost beyond comprehension.
"It began as a small gathering and become a powerful force for good, promoting health, happiness and togetherness," he told Reuters after completing his 568th parkrun in London last week.
"I'm incredibly proud of how far we've come, and even more excited for the future as we continue to inspire people of all abilities to get moving, connect with others, and give back through the spirit of charity and community."
Within parkrun are myriad records and "milestones" - with T-shirts available to mark key numbers for runs and volunteering stints.
The fastest time posted was an astonishing 13.45 minutes in Edinburgh set by Scottish Olympian Andrew Butchart last year, while another Olympian, Northern Ireland's Ciara Mageean, holds the women's record of 15.13 in Belfast, also in 2023.
After winning a bronze medal in the Paris Olympics 1,500 metres this year, Britain's Georgia Bell credited parkrun with re-igniting her love for running in 2022 after quitting the sport five years earlier on the back of endless injuries.
The record for the most runs is held by Darren Wood, who had chalked up an incredible 910 by the start of September having started with the second edition of Bushy in 2004 having missed the first because he thought he was not fast enough.
Parkrun tourism has also become hugely popular, as people try to visit as many different venues as possible, with Paul Freyne leading the way just short of 700.
Myriad other "landmarks" are chased, with Poland, and its seven runs starting with "Z", a popular destination for those seeking to "complete the alphabet".
It has not all been completely plain sailing, however, as parkrun has sometimes struggled to maintain its grassroots ethos amid the behemoth it has become, with the associate costs and need for income streams.
Two years ago former CEO Nick Pearson stood down after failing to declare that he was being paid separately by the manufacturer of the charity's heavily-flagged clothing brand.
Earlier this year, parkrun removed data, including speed records, from its website, saying it wanted to be "less off-putting" to new participants, though many observers judged the move to be a response to criticism that transgender runners had their results listed in the women's category.
It even managed to upset some dog owners by banning waist harnesses on safety grounds, though few of the many runners who had been tripped by them were sorry to see them go.
However, seen against 100 million runs and uncountable thousands of lives changed for the better, they are minor blips in what has been a remarkable 20-year success story.
(This story has been refiled to add a dropped word in paragraph 1)
(Reporting by Mitch Phillips, editing by Ken Ferris)