A runner who completed seven marathons in seven days said it was "one of the most incredible experiences".
Alex Trivino, from Bozeat, in Northamptonshire, wanted to raise funds after his father-in-law, Trevor Davies, was diagnosed with brain cancer in February 2021.
Covering about 184 miles, he started the challenge with a race in Llangollen, Denbighshire, and finished with his final race in Richmond, south-west London, seven days later.
He has so far raised more than £5,000, which he said was enough to fund one full day of research into the disease and was on the way to being able to fund a second.
Mr Trivino said his wife thought he was mad when he came up with the idea but said there were "so few treatment options" for patients.
He said his father-in-law, who is 66, had suffered with seizures for years before his diagnosis, but was told these were due to "low blood pressure".
When Mr Davies was diagnosed with glioblastoma (GBM) he was given radiotherapy and chemotherapy.
Mr Trivino said:
- "We looked up GBM and saw the prognosis which was frightening.
- "Although he has already outlived the 12 to 18 months expectancy of GBM patients, we know that this disease can progress at any time."
Alex Trivino running wearing a white running vest and black shorts. He has dark brown hair and a beard and is wearing a dark baseball cap.
Image source,Brain Tumour Research
Image caption,
Alex Trivino wanted to embark on the 184 mile challenge after his father-in-law was diagnosed with glioblastoma (GBM) in 2021
Despite running regularly and belonging to a running club in Milton Keynes, he said he had never tackled a challenge quite like this.
He said he started training for the challenge in January which would see him run 26.2 miles in under six and a half hours for seven days.
Speaking to the BBC after the challenge, he said: "There was a little moment on Sunday on the last one about nine miles in, where I picked up a couple of niggles from the week and there were a couple of moments where I was like, how am I going to navigate another 16 miles.
"You take it back to why. The reasons why you're doing it. The great money we have raised for brain tumour research and all the positive things."