The Hard-Easy Principle in Running Training

I told you that you progress in your running by applying a stress, allowing enough recovery time for your body to rebuild itself a little stronger, and then applying a slightly higher stress. When you start adding different types of workouts, apply that principle to your training as a whole. You want to start training by the hard-easy principle—you run faster or longer than usual on one day, and then follow that day with a run that’s shorter or slower than usual.
The hard-easy principle helps you in two connected ways. Say I have a fast track workout planned for Wednesday. On Tuesday, I’ll be sure to run very easy. This might mean running a bit less than usual, and it definitely means running at a slow pace for the entire run, no matter how good I feel. This slow pace reserves my body’s strength for the next day and allows me to have a better workout than if I had gone into it more tired. By running easy before a hard effort, you progress because you’re able to get more out of yourself on your hard days.
For at least one day after my fast workout on Wednesday, and more often two days, I’ll take it easy again. After a hard workout, it’s usually easy to go slow enough because I’m beat from the previous day’s work. Taking it easy allows me to consolidate the gains from my hard workout and helps me to avoid injury. If you run too fast or long on the day after a hard workout, then you’re risking injury or staleness later on. Your body needs that chance to rebuild itself.
Remember that the general rule is to plan an easy day the day before a hard workout and allow for at least one or two easy days after a hard workout. By hard workout I mean either a run that includes at least a couple of miles at race pace or faster or a run that’s much longer than usual. What counts as an easy day varies among runners. For some runners, an easy day means a day of no running—that’s certainly a good way to make sure you don’t work too hard! In running terms, an easy day means making sure that you can pass the talk test the entire run.
Before and after fast running, it’s OK to run your usual distance, as long as you keep the pace easy. Before and after runs that are longer than usual, you should not only keep the pace easy, but also run a shorter distance than usual. The longer runs drain your glycogen stores.
The day before, you don’t want to run too far because you might start your long run low on glycogen. The day after a long run, your muscles will still be a little low on fuel, so you’re risking injury if you ask them to go too far.