Jamie Smith, 31, was diagnosed with the neurological disorder – which causes seizures – a decade ago, and says those who have a worse form of it can feel “imprisoned”.
The former Leeds Trinity University postgraduate journalism student, who now lives near Hull, is to take part in the ITU World Triathlon on Saturday, June 9. He is training to swim 750 metres, cycle 19 kilometres and run 7.5 kilometres for the Epilepsy Action charity.
Mr Smith said: “I’ve had epilepsy for 10 years and it has often left me feeling weak, drained and vulnerable.
“I’m very lucky to have a less extreme form of epilepsy, but those with some of the worst forms can be imprisoned by the disease and aren’t able to live a normal life.
“Knowing how hard it is to live with fits, even occasionally, I can only imagine the suffering people who have many a day are going through.
“Epilepsy Action and any sponsorship you give, can really make a difference for these people and their families who can be helped to live relatively normal lives.”
According to the NHS, seizures are bursts of electrical activity in the brain that temporarily affect how it works.
They can cause a wide range of symptoms, such as uncontrollable jerking and shaking or losing awareness and staring blankly into space.
Epilepsy can start at any age, but usually begins either in childhood or in people over 60.
It is often life-long, but can sometimes get slowly better over time.
People who wish to donate to Mr Smith’s fund can visit www.justgiving.com/fundraising/jamie-smith-triathlon