What I have read coe did the 5 pace training invented by frank horwill.
But I cant, from a physiological find the reason for doing shorter intervalls during base. Endurance is endurance and speed is speed. And they get connected in the race season into specific workouts.
I think very few actually do this? But what about doing just milage and intervalls at 5k pace to build endurance together with speed (8x60m, short hills etc…without lactic buildup)
Whats the reason for having intervalls like 12x200m, 10x300m, 8x400m 5x600m during base training?