A man is pushing his body to the absolute limit in the hope he can understand a fraction of what his sister endures every day of her life.
Up until a year ago, Danielle Malley, 39, was an "active and ambitious" mother-of-three.
However, she quickly found herself becoming exhausted with the most minor tasks for no apparent reason.
Her brother Simon Malley, from Aberdulais, explained: "If she cleans the house, she will have to go and sleep for a few hours afterwards. She's got a few young children who run her ragged, someone with normal health would feel tired, but she's absolutely exhausted.
"She's had to give up her job, her hobbies."
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Following a long period of not understanding what was wrong, Danielle was eventually diagnosed with Myalgic Encephalopathy, also known as Chronic Fatigue Syndrome.
He added: "For a year my sister was just like 'What's wrong with me, she was really confused about it, and she just continued to work when she was exhausted.
"It was only when she was diagnosed that there was some help offered to her."
The long-term neurological condition has no cure and still very little is known about it.
Simon said: "It has changed her life from being active and ambitious to being unable to work or continue her hobbies leaving her housebound most of the time.
"Even the smallest exertion can floor her; her joints and muscles ache unbearably, restful sleep eludes her and ‘brain fog’ clouds even the smallest judgment."
Once an avid horse rider, Simon added, "If she rode a horse for an hour she'd have to have a couple of days of being in bed."
In an attempt to raise both awareness and money for the ME Association, Simon has set himself a challenge that he hopes will give him some understanding of his sister's condition.
He will run the world's toughest mountain race, the Dragons Back, which will take him down the spine of Wales from Conwy Castle to Cardiff Castle, 380km and 17,000m - which, to put in context, is almost twice the height of Mount Everest.
He said: "The Dragons Back race was something I thought that if can get through the six days of it, surely by the end of the week, I'm going to need to take a good couple of weeks of sitting in bed, sitting on my backside doing nothing to recover.
"If I wasn't able to go and train do what I do on a daily basis, I know that I would really mentally struggle, so I can only imagine what she's going through.
"She's a strong person, but I know it will be affecting her because she's had to give up all the things she loves, and the kids also suffer because they can't have those things that parents would normally do, taking them out for full days out and things."
Thankfully, Danielle, who lives in Wirral, has her parents to lean on, however, Simon hopes his activities will help improve the future of those living with ME.
If you would like to sponsor Simon, or follow along with his journey, you can find his Facebook page here and gofundme here.
