Why does everyone emphasize Cam Levins mileage as somehow key to his success? Think about former mileage hogs, Jim Ryun and Gerry Lindgren, both of whom peaked at a young age and possibly suffered from early burnout...then think about those with longevity in their careers, for instance Bernard Lagat, who does 60-90 miles a week
Most anyone with a brain would realize you don't need 160 miles a week to excel at the 5000/10000, practically its all about tempo runs at ~10k pace, max V02 sessions at 3k pace, and mile pace training to improve economy, then throw in a little 800 pace stuff for speed
I've never seen how excessive mileage much really matters unless you are trying to do a half marathon or marathon