A brother and sister will run three lengths of the Thames towpath from Weybridge to Hampton Court Bridge to raise money for Cancer Research UK.
John Mannian, 27, will take on the 30 mile challenge on September 6, running from Weybridge Rowing Club to Hampton Court Bridge and back twice in honour of loved ones lost through the years.
Mr Mannian will be joined by his sister Terri, 25, who will complete 15 miles of the run, and his father, Geoff, will cycle behind for moral support.
Despite tough training and sustaining impact injuries, Mr Mannian, who attended Heathside and Brooklands College, said he was looking forward to the challenge.
He said: "It's [the training] been five days a week for the past seven months with a few weeks of resting and trips to the hospital from really painful impact injuries in my feet and knees.
"Eating the right food and giving up beer was tough at the beginning too."
To sponsor, visit justgiving.com/jon2tez or text JMTM86 £1 to 70070.