A SELF-CONFESSED "couch-potato" dad is pushing himself through the pain barrier to help his son who suffers from a rare muscle-wasting disease.

Steven Tinkler, of Darlington, is to walk the three highest mountains in Yorkshire in an attempt to raise £1,000 in the name of his son, Mitchell, seven, who suffers from Duchenne Muscular Dystrophy, for which there is not yet a cure.

A personal fitness instructor, Philip Pentony, 26, of PFit personal training, is giving two free lessons a week to Mr Tinkler so the father can complete the challenge.

Mr Tinkler said: "There's times in training my body is just screaming, 'stop,' but I think about Mitchell and I scream back, 'no.' My muscles will ache tomorrow but that is what Mitchell has every day, every hour and every minute."

The Northern Echo: MITCHELL: Steven Tinkler who is in training to walk the Yorkshire Three Peaks in the name of his son, Mitchell, 7, who suffers from Duchenne Muscular Dystrophy, with personal trainer Philip PentonyMITCHELL: Steven Tinkler who is in training to walk the Yorkshire Three Peaks in the name of his son, Mitchell, 7, who suffers from Duchenne Muscular Dystrophy, with personal trainer Philip Pentony

Last year Mr Tinkler, his wife Kate, their daughter Elliotte, 11, and family and friends raised £20,000 for Harrison's Fund, a charity set up by another family dealing with the condition. However this time Mr Tinkler is raising cash for Joining Jack (JJ), a similar charity.

Duchenne Muscular Dystrophy affects about 2,500 boys and girls across the UK, although only about one per cent of sufferers are girls.

Mr Tinkler said there was good reason to hope for improved treatments and maybe even a cure if enough money could be raised and used for research.

He will walk the Yorkshire Three Peaks of Pen-y-Ghent, Ingleborough and Whernside on Tuesday, June 28. Donate at justgiving.com/Steven-Tinkler2 or search for Tinkler's Rucksack on the justgiving site.