I’m pulling a 50kg sled, very slowly, around Kensington Olympia on a bank holiday Monday, and it really hurts. I’m competing in Hyrox – kind of like the Tough Mudder of fitness, minus the mud – with 7,000 people taking part over one weekend.

Once the sled’s done, it’s onto the 1k run, ski-erg and burpees. It’s brutal. And yet, thousands of us are eagerly signing up every time the competition rolls around to our city.

In just five years, Hyrox has gone from a niche CrossFit activity to a mass participation sport. In 2017, it had 650 competitors in one city; today, they’ve got 120,000 people taking part in 49 cities across the world.

The concept is simple: you run eight 1k runs in between eight functional fitness exercises. You might be fine at running 8k, but when you’re asked to do that after a 1,000m row, a 200m farmer’s carry (holding two 16kg kettlebells) or 75 reps of wall balls, it’s not so funny. How easy, then, is it to get Hyrox fit if you’re not already a CrossFitter?

How to train for Hyrox: “I competed my first Hyrox competition and loved every moment – here’s how I got fit for it in 16 weeks”