Aim for three days running a week. It is preferable to run on every other day in order that you allow sufficient time for recovery.
Day one: 35 minute steady paced run.
Day two: 10 X 2 minutes with 1 minute walk or slow jog recovery.
This should be at the same pace as the 3 minute runs of last week.
Day Three: 1 X 20 minutes steady paced run- 5 minutes walk- 1 X 10 minute steady paced run.
Walkers: 4 x 30 minute walks on alternating days during the week and a 60 minute walk on the weekend.
The distance covered on these walks should be increasing without much trouble.