To better train for faster racing, it helps to always have in mind the five racing abilities. When these basic aspects of running fitness are examined separately, your workouts can be better tailored to ensure you're getting the most from them and meeting your racing goals.
Although in running there are many ways of talking about the same concepts, the five racing skills broken down in the following way, outlined in Brian Clarke's book 5K and 10K Training, offer a path to learning to exert yourself in exactly the way you want to at any given point in a race.
Can you cover the race distance without stopping? Clarke uses stamina to refer to the ability to run long and slow, and always with light exertion--as marked by inaudible breathing at no more than 69 percent MHR. You should feel "held back" when you are properly training for stamina; steady state running is too quick for stamina training. Pace is immaterial, as run-duration is the key factor.
This differs from stamina because it means sustaining uncomfortable race exertion. We all know that short races can cause as much discomfort as marathons, just for a much shorter period of time. The ability to continue at race pace despite discomfort is essential. Endurance workouts, then, demand race-specific levels of discomfort.
That said, an endurance workout should not generate the same level of fatigue as the actual race. Aim in your workouts for a level of discomfort that mirrors the middle-to-late stages of your goal race. By contrast, stamina workouts should not regularly yield noticeable discomfort; if they do, you are probably running too long for your adaptive purpose.
This is the ability to run comfortably at race pace. Whereas endurance can be thought of managing discomfort in the later stages of a race to maintain pace, tempo can be thought of as the feel-good pacekeeping of the earlier stages of the race. Tempo training is among the most important types of training for competitive racing, as it determines how fast you will be able to run the race.