2 min read • Posted February 18th, 2026
Cara Grimwade is soon to take on one of the most extreme ‘triathlons’ we have heard of. Pushing herself to the outer limits of endurance & bravery, Cara will tackle the UK’s two hardest swim-run challenges, combining the Puddle Buckley in the mountains of Snowdonia (The Puddle Buckley Round – A Snowdonian Run/Swim Adventure.) and the Frog Graham in the fells of the Lake District (Frog Graham Round), and cycling between the two. This feat has not been attempted before. Starting on May19th, Cara hopes to complete the challenge in approximately 60 hours, with only three 20minute breaks for sleep!
Here are some incredible numbers to contemplate: 130km of fell running, 7km (8 lakes) of open water swimming, 330km of riding, 34 peaks and 41,000ft of elevation – and just 1hour of sleep!
Cara is raising money for the brain injury charity Brainkind. Having suffered two brain injuries from motocross accidents, and receiving invaluable support from Brainkind, Cara now intends to push herself to the limits of human endurance to raise money for this wonderful charity. Mercian is very proud to support Cara’s efforts. We have donated the frame, and we thank Sunrise Facilities Management for sponsoring the components, and Huub for providing wetsuits and kit.
If you are impressed by this epic challenge, or simply overawed by her incredible bravery, you can donate to Cara’s cause here: Cara Grimwade is fundraising for Brainkind
We wish Cara the best of luck!