The sound of cheering, clanging weights, and pounding footsteps filled the air at Kelvedon Hatch this September as Nuclear Fit celebrated its biggest event yet, welcoming more than 1,000 competitors from across the UK. What started just a few years ago as a small, local functional-fitness challenge has grown into one of the most exciting and inclusive fitness races in the country — and this September’s turnout proved it.
When Nuclear Fit launched, the goal was simple: to create a functional-fitness event that captured the trademark Nuclear spirit, tough, friendly, and community-driven. The first few competitions drew a few hundred eager athletes. Fast-forward to 2025, and the event has more than doubled in size, attracting gym communities, bootcamps, CrossFit boxes, Hyrox athletes, and first-timers all keen to test their fitness outdoors in true Nuclear style.
Each year, improvements have been made, refined course layouts, improved timing systems, team divisions, and spectator zones that bring the atmosphere to life. The September event marked the culmination of that steady evolution, with a record-breaking crowd and a festival-like vibe that left everyone buzzing.
Coverage in publications like Men’s Health and Women’s Health helped shine a spotlight on the format, but it’s the dedication of the local fitness community that has truly driven its rise. Gyms from across Essex and beyond now train specifically for Nuclear Fit, and many return year after year, bringing larger teams and louder cheers each time.
