Clare Balding joins Multiple sclerosis sufferer, Jo Fielder, on a training walk, just before she attempted to cover the entire length of the Ridgeway in just seven days. They were joined by Jo's husband, Jake and former track and field athlete, David Hemery. Winner of the 400 metres hurdles in the 1968 summer Olympics in Mexico City, David has been a source of inspiration and training advice to Jo as she prepares for this challenge. Tune in to find out if she made it.

Map ref: SU 09358 68848 OS Explorer 157 Marlborough and Savernake Forest.

Producer: Lucy Lunt.