I started running competitively last year for my high school team as a senior. I wish I had discovered that I was relatively fast sooner, but what can you do? I'm not exactly sure how fast I can get with proper training, but I didn't get any base mileage and ran 2:03 in my first race a week after joining track. I ran 2:00 the next week and split 51.8 in a 4x4 the same day, then ran 51.75 in an open 400 at our next meet. I went on to run 1:57 4 weeks later by the end of season, but my training was interrupted by a shin injury I got from hitting it hard on a table corner so I just did half my speed workouts since it started flaring up and just ran 2-3 miles a day. Two weeks after season ended I ran 16:44 for a 5K off of my 400/800 training. I'm about 17 and a half; I'm about 5'10" and 125 and no one in my family really has a history of being a fast runner or even athletic. Being able to run close to sub 4 or even breaking it would be a really great accomplishment but I'm not even sure what my best event is.