Forget steep hills, the UK’S toughest parkrun is flat – but covered in mud

♦ Every Saturday morning, come rain, gales or shine, tens of thousands of people drag themselves around a local 5km (3.1 mile) parkrun course.

But while some routes involve killer uphill climbs on tricky terrain, others are a relative breeze along paved sea fronts, prompting a debate about which is the toughest.

Now, an investigation has concluded that the hardest parkrun in the UK is not one of the hilly circuits, but a mud-drenched course in Cumbria.

BBC Radio 4’s More or Less programme compared courses using the average age-graded results, which compare each runner’s result to the world record for their age group.

It declared that Millom, near Barrow, was the toughest course, as it has the slowest average age grade and the highest average time of 35 mins 30 secs, compared to a national average of 28:16.

The 5km loop – five laps around the local primary school – while relatively flat, is usually caked in mud. Regulars are advised to wear football boots instead of trainers and professional rugby players use the course as part of their training.

Since 2004, 1.5million people have taken part in parkruns in the UK. The steepest of the more than 500 courses is said to be Whinlatter Forest Park in Braithwaite, Keswick, which features 230 yards of uphill slog.