Getting results from training is all about managing stress and recovery. Read more on that here. Therefore, as a coach, I like to prescribe easy runs (which should make up 80-90% of your weekly training) in time, rather than distance. I also never give a prescribed pace for these runs, but rather an “effort” rating.
The reason for this is that the total stress of a run on the body is an accumulation of the stress the body is already under (be it from a previous hard training session, work stress, lack of sleep, poor nutrition etc.) and the workload of the run. This means that some days your body will already be very stressed at the start of the run and so for that run to be easy, you need to run really slow. Another day you might be rested and strong at the start of the run and then a much faster pace will feel just as “easy”.
So, by adjusting your pace to how you feel instead of a prescribed pace, the stress of the workout is at the correct level for adaptation. Where going for distance instead of time messes with this is: 1) you will naturally push a little harder to get the kilometre’s finished and your mind will naturally default to calculating pace which will make you not want to go slow. 2) If you are really tired and going really slow, you will end up running a lot longer – increasing the workload beyond what it should be.
So, bring out the old Casio stopwatch and learn to “feel” your runs.
Onwards and upwards!
Faster | Stronger | Together