Castle Race Series, which reports more than 25,000 participants annually to its events in the UK, Ireland and France, has announced a new partnership with truefuels and a transition to the njuko booking platform.
Founded in 2009 with its first triathlon at Hever Castle in Kent, the series is now in its 18th year of operation. For the 2026 season, it will host six festival-style events across five castle locations, offering 122 different race options ranging from junior events to triathlons and run-only races.
truefuels, a sports nutrition brand co-founded by Olympic champion Alistair Brownlee, joins as the Official Nutrition and On-Course Fuelling Partner. The collaboration will see the brand’s products available at feed stations for longer-distance races across all five multisport events in the 2026 season.
The nutrition partnership aims to provide participants with scientifically developed, easily digestible fuel to maintain energy levels and support hydration during competition. According to the event company, the collaboration represents a natural alignment between two brands committed to helping athletes perform at their best, regardless of experience level.
In addition to the nutrition partnership, Castle Race Series has transitioned its registration and entry management to njuko. The move to the new booking platform was driven by a desire to streamline the participant journey through a more intuitive and user-friendly interface.
A new system from njuko has been implemented across the full portfolio of events. Early feedback from users has reportedly highlighted improvements in speed and simplicity when managing entries and accessing event information.
The 2026 Castle Race Series schedule includes events at Hever Castle (Kent), Castle Howard (Yorkshire), Cholmondeley Castle (Cheshire), Lough Cutra Castle (Ireland) and Château de Chantilly (France).
www.castleraceseries.com
www.truefuels.com
www.njuko.com
