TRAINING for the London Marathon has helped Colin Biss to shed three stone in weight.

The vital work of an emergency rescue service is behind the Sherborne dad's decision to go the distance.

Dorset Air Ambulance is the NHS worker's charity of choice to benefit from money he raises.

Colin, 44, of Sherborne, said: "I think it's a vital service for the area and I've often thought about how good a cause it is when I see the helicopter flying over Sherborne.

"There are so many people who use it and who've had their lives saved by it."

Dad-of-two Colin plans to raise £2,000 for the charity and has already had £1,000 in support pledged by friends and family.

He is still clocking up the miles in training sessions and is now up to 15 miles for each run.

His biggest fans - his son Ben, five, and daughter Chloe, eight - will be at the finish line to greet him.

Colin said: "They are really excited about me running and keep asking me if I'm ready for London.

"I'm really looking forward to it - it should be a fantastic experience and a great day out.

"They say it's one of the biggest sporting experiences in the country and it's so good to be getting involved as an ordinary person.

"All sorts of things will be going through my mind as I head towards the finish line, but I'll be mostly thinking of my family."