Joe Lee, who will celebrate his 41st birthday at the start of the challenge on April 5, says the runs along an abandoned railway line near his home at Coton Fields, Stafford, will be “mentally and physically punishing”.
Although he underwent major vascular surgery two years ago he challenged himself initially to run in a marathon in Amsterdam and has since completed one in Spain and the equivalent of 16 others.
A member of Rising Brook Runners, Joe is now in training by running along the former railway track between Beaconside and Newport.
Father-of-three Joe, who works for Staffordshire County Council, is being supported in his efforts by his 34-year-old wife, Sarah, a council contract highways inspector.
He said: “If someone says I cannot do something I like to prove them wrong. I am doing training by running about 40-miles each week along the railway track and back again.
"The railway line where I run is only one mile from my house and I am hoping to raise funds for Katharine House Hospice at Stafford.
"I have set up a justgiving page and hoping for as many donations as possible.”