Stress & Recover Principle: stress the the body in a certain physical discipline and then allow it to recover, and when it has recovered it will comeback better adapted to that original stress.
Running training then, is not about hitting a certain time, it is about getting the desired adaptation. Here is what I think is a good definition to work from, and way to look at, both our stress workouts and easy/recovery runs:
Stress Workout: These are running workouts in which we significantly stress a system or systems of the body in order to produce a targeted adaptation so as to improve certain aspects of our running fitness. Our goal is to do sufficient and specific enough work in order to elicit the adaptation we are seeking, while still being able to recover from that work relatively quickly so we can soon after target another adaptation (as we have multiple systems to work regularly). To accomplish this we want to finish our stress workouts feeling like we have worked very hard, but not as far as having all-out raced our efforts. In order to keep the training process moving forward and to be able to target all necessary systems with adaptation on a regular basis, a stress workout should be able to be recovered from with 1-3 easy/recovery days.
Easy / Recovery Runs: These are runs we do in order to promote recovery and to maintain or advance our body’s adaptations to running and aerobic fitness while we recover from our stress workouts. These runs should be kept relatively short and slow enough that they do not significantly stress the body.
- As a coach I can tell you approximately the pace ranges in which to do certain workouts at in order to target certain desired body systems for adaptation. But these are just educated assumptions based on many, many variables - it is not an exact pace and can vary based on changes to any number of variables. The primary focus then of the stress workout is to get in significant and specific enough stress to gain the desired adaptation and not necessarily to hit a certain time or pace. You should never judge the success or failure of a workout by if you hit a certain pace or covered a certain distance, but rather by if you put in the correct effort and executed the workout in such a way as to significantly stress the system(s) you wanted to target.
- Be careful to keep in mind the need to sufficiently target a system(s) with significant enough of a stress to elicit the desired adaptation. One common mistake I think many runners and coaches make is to utilize mixed workouts too much in which they target many different systems in the same stress workout. The end result of this often there is not enough focus or specificity to the work on any 1 system to gain a new adaptation. Instead I think mixed workouts are better for maintaining the fitness of (adaptations of) many systems rather than improving any of them.
- As a general rule, we do not gain fitness by pushing and improving the pace of our easy/recover runs, but rather the pace of our easy runs improves as we gain fitness.