hey to all of lets run. i just want some advice. im a freshmen in college who doesnt run for a team or anything i just do it cause i love it. i ran xc and track all through high school and my pr's were 800- 1:58 1600-4:34 5000- 16:57. over the next few years im really looking to build endurance because i would love to be able to break 16 minutes in a 5k on a track and think i have the foot speed to be a sub 16 runner. what are some ways i can improve my endurance over 5k aside from just adding mileage which i would like to avoid, due to shin problems? what should my intervals(when i get to interval training) be paced at? thanks to all those who respond