Just wanted to share my high school progression. Unfortunately I got injured my senior spring season but thought I'd share the progression anyway because I feel like you don't really see this type of progression all that often, and it shows the vast improvement all of us can make with the right training and approach. I'd give most of the credit for my progression to the training I was doing... I won't go into too much detail... but I was hitting two workouts a week, 90% being threshold intervals (10 x k, 7 x mile, etc) and ensuring I was going true threshold pace (look up vdot threshold chart to figure out yours and slow down 10-15 seconds off what it says) and always keeping my easy runs very EASY (150-155 heart rate for someone who has a 205 max heart rate). Was at 35 miles freshmen year, 45 sophomore year, 55 junior year, 65 senior year.
People tend to overtrain so easily and I'd give a lot of credit of my progression to just the simple yet smart training that aimed for longevity and sustainability. If anyone wants to know more about my training or progression just let me know...