As my 8 month old CKC Spaniel has only been with me a week and has not yet learned to be obedient, I am keeping him on the lead all the times when we are outside, even in the garden (it isn't fenced off properly and backs onto a busy road). However, I am worried that he isn't getting enough exercise. I have bought a retractable lead but he still doesn't run around as he does when he's no on the lead. Can anybody advise me here, please?

Get the garden properly fenced right away, or at least a portion of it nearest the exit from the house that the dog uses. My dogs have the first 20 feet of the garden fenced in for their use, one of the reasons being that one of the back neighbours hates dogs, and the left hand side neighbour has not got dog proof fencing the entire length!