My PB is 37:01 which I achieved on 45 miles per week (I've also run a similar time on 60 miles per week avg during marathon training). I've plateaued and have tried to improve by going from 2 workouts a week to 3, but that got me injured. I've been running for 2 years pretty consistently.
Below is a typical week of mine (I know, not great). Where I live is pretty hilly. Is there anything major I can improve to break 36 minutes? Perhaps longer tempo runs? My BMI is 19 and I am quite light but somewhat prone to injuries, early 30s.
Monday: 8 miles @ 8:00-8:15
Tuesday AM: 5 mile tempo @ 6:30, PM: 5 miles @ 8:30
Wednesday: 9 miles including interval session (e.g. 6x800, 12x400, mile repeats)
Thursday: off
Friday: 5 miles @ 8:00-8:15
Saturday: 13 miles @ 8:00-8:15
Sunday: off