Jake Mendelsohn from Newton Aycliffe was in action in the Biathlon at Crystal Palace at the weekend.
He knocked 5 seconds off his 100 metre swim time (1.07) and 32 seconds off his 1600 metre run time (5.18), winning both his heats and is now 14th in the UK.
The staff at Woodham Sports Academy have been extremely supportive of Jake, training with him in their own time after school over the last month.
His next challenge is the Great North Swim in Lake Windermere on 12th June which he is doing to raise money for Brain Tumour Research to support family friend Anna Swabey from Newton Aycliffe.