A man who will run the London Marathon barefoot said the death of his father last week has given "new impetus" to his challenge.
Simon Grundy, 37, initially decided to take part so his 77-year-old father, Roy, would have "something to focus on" after being diagnosed with an aggressive brain tumour just over a year ago.
The Australian, who now lives in the village of Much Marcle, Herefordshire, said: "At first we thought dad would come to London to watch me, but then he got too unwell and was planning to watch the race on television.
"He was very supportive. His death has given new impetus to my run and has given me a lot to think about on the day. It is going to be a very, very emotional day."
Mr Grundy, who is raising money for Brain Tumour UK, described how his father started falling over and forgetting things, which led him to have an MRI scan which revealed the tumour. He died last Saturday.
"He had to stop working in his carpet cleaning company, which he loved. He was really excited about the marathon and was helping to organise fundraising events among his friends," he said.
Mr Grundy said his feet were toughened by walking barefoot across canyons in his homeland in blistering heat, and he has been perfecting his technique ever since.
"You don't put your heel down first, but land on the ball of your foot, lifting your toes. You also take much shorter strides.
"It has been a fascinating process," he said.
Mr Grundy added that he has used high-strength glue to treat a wound to his foot.
"Doctors use Superglue and this was recommended to me by several people. It worked really well," he added.
Francesca Towson, Brain Tumour UK's community fundraiser, said: "Simon's determination to run the Virgin London Marathon barefoot for us is very inspiring and greatly appreciated.
"We are so sorry for his loss and will think of him every step of the way. Our team is trying to beat last year's target of £90,000 to help raise awareness and fund research into this devastating disease."