ATW Box End Mixed Team Relay (incorporating British Triathlon Mixed Team Relay Championships)

ATW are the largest multisports organiser in the UK and in 2025 are proud to be organising the British Triathlon Mixed Team Relay Championships.

Join up with your freinds and/or clubmates to take part in the exciting Mixed Team Relay format that saw GB win gold and bronze at the last two Olympics in Tokyo and Paris. 

The format is a team of 4, (2 x Female + 2 x Open category) with each athlete completing their own short triathlon before handing over to the next athlete.

The race begins with a deep-water start by a 'Female' category athlete who will complete a 350m lap in the crystal-blue waters of the wakeboarding lake. Next up is a fast 7.7km non-drafting bike leg that circumnavigates the venue and then finishes off with a 1km out and back flat run along the side of the lake in full view of the transition area before handing over to the next athlete who will start by running in to the water.

The team order in 2025 will be Female-Open-Female-Open

The British Championships will be competing for medals in the Junior, Senior, Vet40 and Vet50+ Team categories. Not all athletes need to be in the same category (see the bottom of the page for more information). Your team will be allocated a category on race day once the team declaration including date-of-birth has been made at registration.

If you would like to take part but do not have a team to enter, we are pleased to be able to offer you a single entry ticket into this event. You will then be assigned in to a team on the day of the event. Where possible we'll try to team you up with other athletes who are eligible for the Championship, but this is not guaranteed, but we will guarantee that you'll get to take part in the fun!

Team entries will be made by the team captain with details of team mates being able to be added later if they are unknown at the time of booking, and a final team declaration at registration on the day. All team mates will need to provide their date-of-birth and Home Nation membership details.

This event is open to everyone, regardless of ability. Teams can participate made up of non-club members and/or members of different clubs, so feel free to team up with family, friends, training partners, or house mates.

In order to be eligible for the British Triathlon Mixed Team Relay Championships, all team members must have a Core or Ultimate Home Nation membership (a race pass does not qualify you for the Championship). 

Transgender athletes are, and will continue to be, very welcome at recreational and competitive activity in Triathlon. The Female category is defined as athletes who are the female sex at birth and the Open category all other athletes.

As the bike leg is held on public roads, the minimum athlete age is 16 on race day.

The relay will begin at 6:30pm on Saturday evening. 
After the racing has finished, there will be live entertainment, a bar and food available on site.

On the Sunday morning, Box End will play host to a 100k Centurion Triathlon and a Sprint/Standard distance Tri. With camping available on site, this will make an ideal weekend away. For more information and to book your camping tickets, click HERE     

Need to hire a wetsuit? We are pleased to be able to offer Zone3 wetsuits. More information

Reasons to enter this event:

Stunning clear waters, beautiful venue, fast bike course

Well-marked course with the best marshals

Custom designed medal, Finish line snacks & goodies and Free event photos

Live entertainment, food, bar and camping on site

Team Categories (ages as at 31/12/25)
Junior Team - all team members must be age 16-19 (note athletes must be 16 on race day)
Vet 50+ Team - all team members must be age 50+
Vet 40 Team - all team members must be age 40+
Senior Team - all other combinations of age categories

Event Organiser

ATW was established in 2011 by James Shipley. We have now become a national events company in the UK, specialising in Running, Triathlon, Duathlon, Aquathon, Cycling, Swimming and all permutation of swim-bike run events. With over 40,000 entries a year ATW has become a firm favourite amongst people who are determined to Dream, Believe and Achieve.