AFTER a virus left him seriously ill, Dursley dad Damian Lai vowed to lose weight and took up running – and now he's set for his biggest challenge, the London Marathon.

Father-of-two Damian, 39, is running the marathon this Sunday to raise money for the British Lung Foundation (BLF).

In January 2014, Damian had a virus which attacked his body, leading to him developing severe pneumonia.

His antibiotics didn't work and his immune system didn't fight back.

Eventually, he had to have an operation to remove the infection and, after three weeks in hospital, he decided to turn his life around.

Nearly 20 stone at the time, he took up running in January 2015.

“With my old lifestyle I would have been lucky to live to 50, I had to do something," Damian said.

"I've got a lovely wife and two young boys. I’m very lucky and they are really proud of how I've turned my life around following the illness.”

Damian, whose father also has industrial asthma, decided he wanted to run for a charity close to his heart.

He’ll join over 100 other runners as part of the BLF’s #TeamBreathe marathon running team, and is hoping for as many people as possible to come out to add to the atmosphere.

Damian hopes his marathon effort will not only help increase awareness of lung disease, but raise over £3,000 for the BLF’s research, support and campaigning work, fighting the impact of lung disease throughout the UK.

Commenting on his decision to run for the BLF, Damian said: “I was very ill in 2014, but the care I received was second to none. I feel very fortunate to have been cured.

"By helping charities like the BLF who make a difference by funding projects, I can help make sure that one day everyone breathes clean air with healthy lungs.

“I needed to do something special if I was going to raise lots of money, and my dream was to run the London Marathon.

"In the past it could only have been a dream, but I've been on a life-changing journey since early 2015 when I took up running. I'm 12.5 stone now and my life has completely changed."

Katie Lyall, Community Fundraising Manager for the BLF, said: “We’re incredibly grateful to Damian for his fantastic support. It’s thanks to the amazing fundraising efforts of people like him and the rest of Team Breathe that we are able to continue our vital work, researching new treatments and supporting people living with lung disease across the UK.”

Anyone who would like to support Damian can visit http://uk.virginmoneygiving.com/DamianLai