One woman’s 50th birthday challenge in aid of a nine-year-old boy with a life-limiting genetic condition has inspired dozens of people to join her for a triathlon and fun run in Codicote on Sunday.

Pilates instructor Vikki Davis wanted to do something special for her landmark birthday which would raise money for William Eames, who lives in Codicote and has Duchenne muscular dystrophy - a progressive and incurable muscle-wasting disease which has already made William dependent on a wheelchair and will severely limit his life expectancy.

Vikki set herself the target of swimming 1,250 metres, cycling 50 kilometres and running five miles back-to-back to raise money for him and for a charity working towards a cure. More than 40 others are joining the challenge, with dozens of families from the village also expected to take part in the running stage of the event.

Vikki, who is best friend's with William's mum Jo, said: “We see every day how much effort William puts into school and getting around while also doing daily physio and enduring hours of hospital appointments. This is going to be a tough event for everyone taking part, but we’ll all be thinking about William and how strong he is, to get us through.”

Participants will cycle from Codicote to Hatfield Leisure Centre for their swim, before completing the rest of the 50km cycle, followed by a five-mile fun run back in Codicote.

More than £8,000 has so far been raised, which will be split 50/50 between national charity Duchenne UK and a local fund - Defending William Against Duchenne - which helps William and his family deal with the impact of his disease.

Jo said: "William's condition is continuing to decline, which is heartbreaking to watch. Ultimately, there is no cure but, with the support of Vikki and our amazing village of triathletes, we find hope by funding research with Duchenne UK.

"We have a family fund under Duchenne UK, which means all the money raised can be directed to research which benefits William's particular mutation of DMD.

"We are continually grateful for all of the support we get for our son and family."

To donate, visit justgiving.com/crowdfunding/triathlonforwilliam. For more about William, visit facebook.com/DefendingWilliamagainstDuchenne.