Intervals are something that you can incorporate into your training to help you increase your speed over a longer distance. We take shorter distances, we break it down and we do that at faster speeds so that your body slowly adapts to running more comfortably at those slower speeds.
So say you're running ten minutes miles, so we're going to take half a mile and have you run that at maybe four minutes, or maybe four and a half minutes. So again you're actually running those shorter distances at a faster speed than you're already running maybe you're five mile pace at for ten minutes.
So slowly but surely you're going to start adapting your body. It'll get used to that faster speed and as you go out for your longer run that ten minute mile will start to feel easier. So slowly but surely you'll start to be able to run a little bit faster for those longer distances.
So we're going to do a speed workout and our speed workout is six to eight 400 meters or six to eight 800 meters. Those six to eight repeats are your intervals. The reason why we're doing it is because we're challenging a different system of your body. Your body has a threshold at which it can process lactic acid. That lactic acid is that burning feeling when you start to go a little bit faster than you're used to. So what the intervals do, it helps your body adapt to that feeling of lactic acid and helps your body metabolize that lactic acid a little bit better so it starts to flush it out at a quicker speed than it was able to before and that's why those ten minute miles no longer feel so challenging and you're able to get a little bit faster through that interval training.