A couple years ago in my senior year of xc in high school my coach had us doing a lot of 6-8x600m and 6x800m. I don't remember all the workouts but on several of them leading up to the great american xc festival we were doing our eights with 2:30 or under less (one time 2 min) and at about 2:25 to 2:30 pace. My heart rate was typically near 190 to 200 (hand measured). These were definetly almost all out efforts and that is how he wanted them.
For the 600's i would run near 1:45 to 1:49, with likely 2 to 2:30 recovery (can't quite remember those). Either way they were near mile pace and this was in september around 7.5 weeks before state (the target race). I felt great at the time. After 2 or 3 weeks of workouts like these i had 30 second PB at the great american 16:40, but after that race I was completely dead. In all my 800 workouts after that I struggled to consistently run 2:35's and ended up running the same time at state as I did the year before.
Were these midseason specific endurance (as i think its been called) workouts the primary source of my physical burnout and the mental one that followed?
Or was it more likely to be attributed to months of overtraining? In the summer we upped the pace of our run as compared to years before and incorporated weekly/bi-weekly long runs. We also were running doubles 4 days a week with light 3-4 mile runs in the morning.