The Animal Within wrote:
Id like to challenge you to change your thinking. Don't think of 12 milers as long runs. Think bigger: 18-23+ are long runs.
But I really think 12-14 miles is enough for developing adolescents in HS. The consistency of running 60 minutes per day is much more valuable.
And your hard workouts may seem mundane but when done right can get you to that 9:15.
Well if he's only doing in the 50-60 mi range then 25% of weekly mileage is 12.4-15 miles so that is plenty long. 90-105min Long Runs should be good for him