Kim and Richard Rawlings are planning to cover the route in just 11 days in their boot-testing effort to raise as much money as possible for two worthy causes.
While Kim, from Craven Arms, is hoofing it for the Hopton Rehab & Homing Centre for horses, Rich is hoping to help Shropshire Rural Support.
They started their trek before the crack of dawn on Tuesday (September 21) with the good wishes of supporters ringing in their ears.
Lin Marriott-Lodge of Hopton Rehab & Homing Centre, which is based in Ludlow, wished Kim and Rich all the very best and thanked them for their sterling efforts, which should end on October 1.
"They are both into walking," said Lin. "And they are camping at night and I couldn't do that."
Over the next week and a half the dynamic duo will be treading their way to Severn beach via Shrewsbury, Bewdley and Gloucester before a well earned rest.
Lin said she is very grateful for the couple's efforts on behalf of the charity she jointly set up in 2017 with Tracy Cooper.
"We started out as a charity to look after horses that had been injured or pushed too far," said Lin. "They were mostly with physical injuries. Now we also take horses where their owners cannot look after them any more, maybe if the owner has cancer, and we can find them another home."
But it is a hefty bill in hay alone for up to 50 horses that are housed across the charity's three rented yards.
"We have a lower number of horses at the moment," said Lin. "So we have been able to save some money from last year towards the £6,000 it costs for hay alone to keep them fed. We have been fundraising but we don't quite have the £6,000 yet.
"Kim and Rich's efforts are much appreciated - walking between 20 and 26 miles a day is an amazing effort."
Shropshire Rural Support, based in Shrewsbury, was set up in 1991 to help people living in rural Shropshire by providing confidential support during periods of anxiety and stress, and with problems relating to their families and their businesses.
Kim's fundraising page is https://uk.gofundme.com/f/kim039s-campaign-for-hopton-rehab-amp-homing-centre
Richard's fundraising page is https://www.goldengiving.com/fundraising/Richards-walk