John Kirkby, 50, set off on his first marathon in bleak and drizzly Edinburgh and will run marathons in Newcastle, Nottingham, London and Bradford, before flying off to Australia for five more marathons. The last five marathons will be run in New Zealand.
The gruelling challenge has so far raised more than £277,000 but Kirkby is hoping to break the £500,000 barrier by the last run.
With families across Britain struggling in the economic downturn, Kirkby says he will be reflecting on the Bible-inspired message to remember the poor as he runs.
"I'm doing this run to remind us all that no matter how bad things get for the majority of us, they are so much harder for people living with real poverty," said Kirkby, who founded CAP 15 years ago after financial problems of his own.
"When you haven't got a lot to start with, it takes very little to throw your finances into crisis and it is up to all of us to make sure that even when times are hard, we don't give up helping those who struggle to achieve the most basic standard of living."
CAP has grown in the last 15 years from one man with a £10 donation working from his bedroom office to a network of 190 debt help centres currently carrying £71 million of clients' secondary debts.
The charity provides debt counselling to people in need through local churches and opened new centres in 37 locations last month, including in some surprising places like Windsor and Canterbury.
CAP's CEO Matt Barlow said: "Our experience shows that there will be people in each of these areas who think there is no hope and in fact, our research shows most people wait to get debt help because they don't think there is any available. Creditors will be ringing all day, the letters will be piling up and their sleep, health and relationships will all be suffering.
"The fantastic news is that due to the commitment of their local church, we will be able to support each client by seeing them in their own home, contacting their creditors on their behalf, setting them a budget and staying with them until they are debt free."
Check out more about John's run and follow his progress at www.cap15.org