In researching the Ingebrigtsen training there is a clear lack of traditional long runs(20-25% of weekly mileage), instead going 90 minutes at a decent pace which seems short considering their weekly mileage. Most of their volume is in long threshold workouts and even easy days are split up into 2 runs so no single run is very long. Combined with their lack of traditional tempos, it seems that their program emphasizes frequency (doing doubles most days, even doubling workouts as well as splitting up threshold to get more total volume) over duration(20 mile long runs, long tempos etc...) This conflicts with alot of traditional though on endurance training, but clearly produces results. Are we overemphasizing long runs? Are traditional tempos not as good as we think?