Running a Time Base

Many runners plan their long slow distance (LSD) running to cover a certain number of miles. Some runners, however, plan their LSD running to cover a certain amount of time. As we plan our running, we need to decide if we will plan miles or hours. I think this topic is an important idea that every runner should understand.

Advantages and Disadvantages of a Mileage Base

We are conditioned by society to think of distance as miles. Planning a route in miles has the advantage that one always know how far they have gone. It has the disadvantage that one can easily run too far for their present condition. Our body condition, our ability to comfortably run a particular distance varies from day to day. However, many (most?) runners don't change their distance goals on a daily basis. This means that if one is tired, they will probably push to reach the goal for that day and overextend themselves. We all have probably experienced this -- we run past the point of comfort and run until we're tired, sometimes really tired.

Advantages and Disadvantages of a Time Base

Rather than run a particular distance, some runners run a particular time. This means that on days when they feel really peppy, they will run faster and thus farther. And, on days when they feel tired, they will run slower and thus less distance. This means that they have an automatic control on their running such that they are less likely to overextend themselves (assuming their time-goal is realistic and not an over-extension in and of itself). This control is important, because it reduces the risk of injury. It also means that as they get stronger due to a larger base of long slow distance, they will automatically increase their miles while still running the same time. I really like those advantages.

There are two disadvantages of a time base for LSD. The main disadvantage is if one is following a training plan that specifies miles. The other disadvantage is if a non-running friend asks how far they are running, and the runner answers, "An hour"; the friend probably won't know how to relate to that response. You can get around this disadvantage by quickly converting your time to miles and answering in miles, even if it is just an estimate of the distance (the friend probably doesn't want an exact figure).

Go with Time for LSD!

I strongly urge you to run a time-base instead of a distance-base for your LSD. This will reduce your risk of injury and will allow you to avoid pushing yourself to meet an artificial goal of so many miles. After all, your body doesn't know anything about miles, but it does know about time.

Not all runs should be Time Based

In this page, I've limited my comments to LSD, that is general aerobic, easy, and recovery runs. There are, however, other runs for which mileage base is more appropriate, such as tempo and race-pace runs that are geared to a particular pace.