To ensure you get the most out of your time running, you should make sure you aren't performing a workout "just because". It pays to know why you're doing what you're doing.
Here's a problematic example: I want to run a half marathon, but I'm not sure how to train for it. The internet must have the answer, so I search and find 100's of programs I could use.
After careful consideration -- that is, picking randomly -- I decide to use a Hal Higdon program. Now I'm no novice, so I choose his intermediate plan.
This plan has a number of wonderful types of workouts. Everything from tempo runs, to intervals, to long runs. Rare for a plan, it also explains the types of runs which are to be completed. It explains the how of each run type, but does not touch on the why you should be performing it.
As I begin to follow the training plan, I run the pace it says I should run and hope for the best.
After the first month I hit a speed bump. I'm sick for a few days and skip the scheduled workouts.
Now that I'm off the beaten path, I feel lost! I just skipped a tempo run and an easy run. Should I make those up? What was the purpose of that tempo run anyway?
The next day I'm at my track club running some hard intervals. Half way through the session I'm completely spent. Should I try to keep going even though I can't run the speed I want, or should I just stop?
It's tough to make decisions and adapt when you don't know the purpose of you actions. If you're going to spend the time and effort performing a workout with the intent of improving your fitness, you must know the reason behind it.
Running an interval workout vs. tempo vs. easy vs. long run, they each have different purposes. Sure they're all running, but they are focused on achieving and improving specific components of your running.
A body builder rotates through areas of the body, targeting specific muscle groups. She doesn't go to the gym and just lift as many weights as she feels like in whatever manner she fancies that day and expect to improve her strength. A body builder has a purpose and a method of achieving it.
The purpose of the run varies depending on which type of plan (and coach) you're utilizing (you do have some type of plan don't you?!), however here are standard types of runs. Understanding these types of runs will improve your confidence and help your decision making:
- Threshold Training (Tempo Runs/Cruise Intervals). This should be "comfortably hard" running, explained best by Jack Daniels:
With threshold-intensity running, the physiological benefit is to improve endurance: the ability to endure a greater and greater intensity of effort for a longer and longer period of time.
Remember that the purpose of the workout is to stress lactate-clearance capability, not to overstress that capability. I refer to threshold training as "comfortably hard" running. It shouldn’t feel "hard," which is the pace of pure interval training.
Easy Runs. Running easily builds up resistance to injury, helps develop the heart muscle, and increases vascularization. The benefits here are realized more as a time spent than distance covered.
This should be your staple run for building up your aerobic engine.
You can either try to race with an engine the size of a lawnmower, or you can build your engine up with a good base so that you are racing with a huge-turbo charged jet engine.
Long Runs. Typically an easy run, which is simply longer than the normal easy run. It has the same benefits as the easy run, in addition to being a terrific confidence boost. It also teaches you to be on your feet for extended periods of time. This is crucial for marathon and half-marathon training.
Marathon/Half Marathon Pace. Running at your targeted marathon or half marathon pace builds confidence you can handle the pace for a prolonged time (and is faster than an easy run), while allowing for exploration of fueling techniques. Not surprisingly, this type of run is particularly useful for those attempting to complete a marathon or half marathon.
Interval Training/Speed Work. This has a myriad of meanings, but the over arching idea is to run at 98-100% Heart Rate. Running at this pace is typically not done for more than 5 minute at a time.
The goal of this type of training is to improve your VO2max.
It is easy to overdo this type of workout, by either doing too much or going too fast. Working at a hard rate does not mean "all out". You should not be so sore that you couldn't perform an easy run the next day.
Keep in mind that there's no magic to this type of run, Arthur Lydiard went so far as to say a runner should, "Go until you feel you have had enough for that day."
Repetition Training. The primary purpose is to improve speed and running economy. This is practicing running really fast, but taking enough time to recover completely between reps.
You must be full recovered in order to run fast and with good form. If you're struggling to keep good form, you're not accomplishing the purpose of the workout.
Before you go out for your next run, ask yourself, "what is the purpose of this workout?"
There is nothing wrong with not having a purpose for a run, so long as it's on purpose. If you are actively telling yourself, "this run has no purpose other than I wish to run", then you still have set a purpose for the run, enjoyment! Those runs are some of my favorite!
If you're interested in learning more about training paces and purposes, I highly recommend the book Daniels' Running Formula-3rd Edition.