Weight Training for the 400

Bump…with a new question

How would you fit endurance exercises in a program where you lifted 4 days a week? I do 2 upper body/2 lower body days a week (at least for awhile anyways) where I do upper body on tempo days and (because I have to lift in the mornings) was going to do endurance exercises during the track workouts and lift for strength in the weightroom. Would that work or is that too much?

anybody took a look at what i wrote under Sprinting Lifting routines?