The One on The River takes place across the scenic Thames Valley area.

Swim the river, cycle the hilly open roads, or run the flat Thames path – with a mixture of grass, tarmac, and trail – taking in the views of Marlow and the surrounding areas.

Join the Triathlon for the ultimate challenge, or either of our Duathlon/Aquabike categories if you prefer to focus on specific disciplines. If you only fancy a dip in the Thames, then pick one of our swim-only categories instead and get yourself wet!

With multiple distances for each discipline, you’ll find something to challenge yourself this year.