I am a painfully average runner. I train once a year to prepare for the USMC physical fitness test. But this year I have decided to attempt to run the mile in less then 5 minutes. I read that the oldest person to ever succeed at this was 65 years old, so I am determined to do it. Having never seriously trained for that kind of speed I have no idea how to start. Can someone suggest how a 33 year old late-bloomer should begin training to run a mile in less than 5 minutes. Thank you for your time.