When progressing in interval training, which is the best method:
(1)Reduce recovery while maintaining intensity/pace?
(2)Increasing intensity/pace while maintaining recovery?
(3)Maintaining recovery and pace, while increasing distance?
Would the event being trained for make a difference in which method to choose?
It depends on who is doing the workout and what kind of workout you are doing. However, decreasing the recovery while maintaining the intensity is always a good sign that you are in good shape. Here is a rule of thumb I use with my athletes.
For Race Specific workouts (Ex: a 5k running running a workout at 5k pace) I always try to reduce the recovery before uping the intensity. I like continuous running workouts like fartleks, or time trials at a set pace (like 3k @ your 5k pace + 5x400 @ goal 5k pace w/60 sec rest). Or over/underdistance time trial.
For workouts that are faster than your specific event I always keep the recovery time the same and try to increase the intensity. For example: a 5k running who is running 8x300 at 1500 pace w/2 min rest. I always keep the 2 min rest, but the goal is to up the intensity of running.
I've found this works pretty good for all runners from 800 to 10k.
Thats the dumbest thing Ive ever heard.