I understand their concerns.
Where I live is very rural with lots of commons and farmland, green lanes, footpaths, friendly farmers and woodland, but for a year I moved in with my ex, to a very 'trendy' village in the Midlands.
I soon discovered that it was surrounded by big fast roads with no footpaths, endless lorries and fumes. The local estates were obsessed with keeping people out, there were very few footpaths, no stiles and the one local estate where we were allowed to walk, the owner tried to charge £200 a year for a 'licence'.
So my only option was to run around the village - down the lane, up past the allotments onto the high street and back home.
I bloody hated it. it became my one square mile exercise yard. I was miserable. No wonder so many people are overweight if they have nowhere to walk. If I wanted woodland I had to drive 17 miles. Or walk around the local crematorium among the dog poo. It was dire. I lasted less than a year.
So obvious places to suggest are near the coastal path, Salisbury plain, close to the Ridgeway or Icknield Way, close to national parks etc.