8 minute mile is 7.5miles an hour. Anything slower than 6mph I would consider jogging. If you are normal weight, you can train up to that mileage in a few weeks or months if you are healthy even with no background in running. It's by no means impressive nor a shitty running time unless it's your full out max effort best mile time. 8 minute miles are great if you are doing a few miles and aren't competitive. You will probably be faster than most casual runners.