“ALL human life is here.” This truncated quote from the writer Anthony Burgess is a favourite of mine. We can each draw our own meanings but, for me, these five words sum up the kind of joyous moment when you find yourself gazing upon a magnificent smorgasbord of people joining together.

It is a quote that popped into my head a few weeks ago while standing shoulder-to-shoulder with several hundred strangers on a lochside path at Strathclyde Park in Lanarkshire.

I was attending my first parkrun, part of a series of free 5km (3.1 mile) events held at almost 800 venues across the UK each weekend (as well as in a growing number of international locations from Australia to Namibia and Poland to Japan).

As I looked around the sea of faces, I felt instantly at home. There were babies and toddlers being pushed in buggies, lanky teenagers, twenty-and-thirty-somethings, the middle-aged (like me), right through to sprightly septuagenarians.

Oh, and dogs too. One of the best bits about parkrun is getting to meet dogs.

But what makes parkrun most special is that each event has a roster of dedicated volunteers. Every weekend people selflessly give up their time to put on a fun run for others.

They act as marshals, timekeepers, photographers and pacers, set up and pack away equipment, scan barcodes and process results, write round-up reports and update social media.

And it is not the same group of volunteers who do this each week – everyone takes a turn. The parkrun story is one of fortitude and friendship.

The idea was the brainchild of Paul Sinton-Hewitt who, while newly unemployed and unable to race due to injury, began organising weekly timed runs for a few mates at Bushy Park in London. Soon, numbers began to swell as other people rocked up asking to take part too.

That was 2004. In the two decades since, parkrun has grown into a global phenomenon. At the heart of its ethos is inclusivity, fun and community.

Although I have been vaguely aware of parkrun for many years, I never quite understood what it was all about. Yet, from my very first one, the relaxed atmosphere, camaraderie and huge sense of achievement had me hooked. I have now been to five in a row.

Read more: How I became a running bore – trainers, toilet breaks and TMI

Over the summer months, a group of friends and I are doing a spot of parkrun tourism. In recent weeks we’ve been to Auldcathie District Park in Winchburgh, West Lothian (one of the newer events, it made its debut in January).

And last weekend we ventured to Palacerigg Country Park in Cumbernauld, Lanarkshire, where the course was “undulating” and the midges fierce (the excellent volunteers were on hand with a spritz of Avon Skin So Soft to swiftly counter the latter menace).

This Saturday we’ll be making like Willie Nelson and on the road again for another jaunt. As someone who previously used weekends for sleeping in, I am now that person eagerly setting an alarm to go run in a random park somewhere.

I love the pre-run briefing and cheering for those reaching a milestone, such as their 25th or 100th event. Or hearing how far people have travelled – the other week at Strathclyde there were visitors from Barbados and Canada.

The other brilliant thing about parkrun is you don’t need to run or even jog – you can walk it. Afterwards you can go for coffee and cake, pick over the bones of the week with pals, gently tease each other and laugh until your sides ache.

Oh, and then there is the accompanying app which, as well as recording your weekly efforts, comes with a quirky list of challenges to tackle.

If you’d have told me that I would become obsessed with seeking out event numbers that match the Fibonacci sequence or trying to get a palindrome finishing time, I’d never have believed it. But here we are.

And therein lies the magic. See you at the start line on Saturday.