The millionth parkrun took place on Saturday, acting as a celebration of the community cohesion and public health benefit that the charity has been aiming to achieve across the past two decades.

Those in attendance at the event in Bushy Park in west London included former Olympic champion Dame Kelly Holmes, as well as thousands of locals and parkrun fanatics alike.

“Parkrun is one of those rare successful social movements that have happened organically,” said parkrun’s global chief executive, Elizabeth Duggan. “It’s not that we’ve had to pay vast amounts of money to grow the brand and ethos, it just happened from one person to another.”

The free weekly 5km event, founded by Paul-Sinton Hewitt, began in Bushy Park, Teddington, in October 2004 with five volunteers and a small group of 13 runners. It has since grown into a global fixture of weekend life, taking place in parks, fields, seafronts and even prisons.

Initially a single timed run, the event now operates at 2,800 locations worldwide, with more than 12 million people registered to take part.

Every Saturday morning, tens of thousands of runners and walkers turn up to jog, push prams or simply complete the course at their own pace.

These events, which are entirely volunteer-run at a local level, have seen bridal showers in matching headdresses, milestone birthday parties, and even engagements at the finish line.

But beyond giving people the opportunity to run and have a controlled space to move their bodies in for free, Duggan argues that one of the greatest successes of parkrun has been its ability to bring people together from across neighbourhoods – and into a shared green space.

“There’s a huge spectrum of people coming together at the parkruns, and there’s something so lovely about young and old, fast and slow, children and octogenarians all doing something together,” she said.

Whether volunteering or running, she has seen many cases of the local parkrun giving people a sense of purpose. People, she says, are always looking to be a part of something bigger than themselves – and the charity is proud to continue to provide the space.

“It is like a spiritual home for some people, some have likened it to a church,” she says. “It’s somewhere that you go, you know people, it calms and connects. It plays a role in community, and people are keen to support and protect it.”

The appeal lies less in competition than routine. Finish times vary widely, and organisers say the average is now the slowest in parkrun’s history, which may reflect a growing number of beginners and walkers taking part for health, rather than speed.

That shift is echoed in the people it attracts. About one in five participants describe themselves as inactive when they first sign up, while almost a third come from lower socioeconomic groups, suggesting the weekly run is reaching people who might not otherwise engage in organised sport.

However, there is still space for performance. The fastest recorded times stand at 13 minutes 44 seconds for men and 15 minutes 13 seconds for women, both set in Belfast. But for most participants, the focus is simply on finishing.

The movement has also become part of public health policy. More than 2,100 GP surgeries in the UK now “prescribe” parkrun to patients as part of social prescribing schemes, encouraging activity to support physical and mental health.

Sport England research has linked participation to reductions in conditions such as depression and diabetes, as well as fewer GP and hospital visits.

At a community-level, parkruns have given groups the space to share their history and cultures with other people in their areas – for example when Burgess Park parkrun hosted a celebration of Ugandan independence day in 2022.

It also connects people with their natural environment, something that has double the benefit to exercising indoors, Duggan says.

Its reach extends far beyond parks – about 25 prisons and young offender institutions now host parkruns, involving more than 12,000 people in custody, in programmes designed to support rehabilitation.

Duggan describes a case of a grandmother who was incarcerated, who would run the parkrun in the prison while her grandson would run it in his local park. When they would phone during the week, the pair would discuss their parkruns and compare stories from the weekend. “It was something that united them even if they couldn’t be together,” she said.

The charity is positive that they will be able to grow and reach even more people. Over the years it has drawn in everyone from Olympic champions to politicians, including Alistair Brownlee, Ed Miliband, and the late Keith Flint of the Prodigy, alongside thousands of first-timers.

“Parkrun is a piece of me,” says Holmes, who took part in the millionth parkrun on Saturday.

“I love the social interaction of it. I’ve spoken to so many people at parkrun over the years and so many people have told me how parkrun has saved their life.

“That’s everyone, from people who have come back from surgery … [and] women who have given birth and are getting back into activity. It’s for everyone really.”

Moving forward, parkrun is hoping to get even more people from a diverse range of communities participating in physical exercise, especially those from a lower socioeconomic background.

“Lower socioeconomic groups and ethnic minorities are statistically more likely to be inactive,” Duggan says.

“So by expressly targeting them we know that we’ll be having a bigger impact on the health of everyone in the nation.”