Running high-volume workouts at paces between 90-110 percent of lactate threshold, running a lot of easy mileage, and staying neuromuscularly efficient with strides, hills, sprints, and possibly weights and plyos will get you 97 percent of the way to your goals, for events including the mile and up.
You only need to do the bruising workouts like 400s at mile pace, 1ks at 3k pace, etc in the last couple weeks before your goal race to eke out those last few percentage points, and even then, not everybody responds well to traditional sharpening.
We should all take a step back from this view that if I do x workout I can suddenly run x time in a race, until it is really time to peak. Most of the training cycle should be spent performing workouts that are quite controlled and that do not elicit high quantities of lactate.
I don't think you need to do long reps (3 minutes or 1k+) at anything faster than CV pace for the majority of the training cycle. A lot of 400s at 5k pace with short rest is a great session, as are 300s at 3k pace. 150s to 200s at mile pace.
I know I'm not the first person to realize or write this. WeJo knows it. JK knows it. Lydiard knew it. Canova knows it. And many more coaches who are smarter than me. But it's important to think about and truly grasp. It took me a couple training cycles to put into practice. And it worked! I got much faster. I believe it can work for anyone who tries it.