I did that last year and ended up with a stress fracture in my foot and later a major knee issue. Take your time. Run a few times a week and most importantly, don't go from 1 mile to 4 miles to 8 miles, etc. Make sure you start at 1 to 2 to 3... etc over time. I would even dare say about every week or 2 increase your distance by a mile to help prevent injury.