I am 20 years old, and here is the current progression of my times.
16- 4:36
17- 4:32
18- 4:23
19- 4:19
20- 4:14
I have never trained for the mile, but mainly trained for longer distances, which I feel I'm better at. I think if I tweeked my training, I could have been more like 4:10 at 20 years old. Either way, 4:10 and 4:14 are lightyears from 3:59. I figure the average runners Peak is at age 26 or so, so would this be a long enough time for me to go under 4?