Junk miles are a frequently discussed, and often debated concept in running publications and communities. There are valid points on both side of the argument which can make it difficult to know where they fit into your training.

There is one slight problem. If you search “junk miles” in Google and look at just the first page of results, nearly each website will have a different definition and idea of what junk miles are. How can there possibly be a worthwhile discussion when we don’t even know what exactly we are arguing?

Some of the definitions I came across include:

“Relatively short, slow runs undertaken within a day of a harder run”

“Miles added to a training schedule with no other purpose than to increase your milage count”

“Training that does not improve cardiovascular fitness”

“Miles ran with no real training purpose”

“Running the same old route over and over with no variety in training”

“If you are doing so many miles that you can’t get in your speed workouts at a time when your speed workouts should be the focus”

“Running slower to keep your pulse in its normal range because your body is tired from some previous workload”

Some of the above definitions only look at a specific aspect of junk miles, others only define specific ways junk miles can be used while some are just unnecessarily complicated.

Note: Junk miles is often confused with recovery runs, however their meanings are completely different. A recovery run is a slow and short run on the day after a key session. Some runners consider recovery runs as junk miles which may be the reason for the confusion.

Do Junk Miles Apply to You?

Junk miles are not the same for all levels of runners. Any type of running, no matter what speed will benefit a beginner runner. However, more experienced runners need to pay more attention to their training schedule to see improved performance.

Junk miles are different for beginner and experienced runners. Junk miles become more relevant and important to minimize as the runners experience increases.

Additionally, junk miles are only relevant for runners working towards specific goals. It is impossible for a runner with no goals and just running for fun to run a junk mile. Any type, distance and speed of running is acceptable and accomplishing what the runner wants.

Junk miles are only relevant if you are working towards a specific goal or race.

What Are Junk Miles?

Junk miles do not mean slow running. The confusion with the term probably started when some guy that hated doing slow runs started to call them junk miles and the term caught on and spread. A good training schedule varies and includes both high and low stress workouts.

Junk miles is all about the tradeoff between training volume and training stress. When working towards any goal, there will be an optimal amount of each. Junk miles are when your training volume is too high, not allowing you to do your workouts at an optimal amount of stress.

In the above graph, the pink area shows the point where overtraining occurs. The left hand example gives an example of a runner that needs to decrease training volume to increase training stress and eliminate junk miles in the process. The right hand side gives an example of a runner training that is overtraining and needs to eliminate junk miles for optimal training results.

Why to Ignore this Definition

I believe that no runner should take the junk miles definition seriously, unless if you perhaps are training at an elite level. Junk miles takes on the approach of a pure performance based schedule. It does not take into account many aspects and often takes the fun out of running.

Junk miles are different for everyone depending on experience and the goals you are working towards, therefore a single definition cannot be effective. A more relevant way to use the concept is to identify certain situations where junk miles may or may not apply:

  • Doing speed work at a pace you are not ready to do are junk miles because you will get injured and training will stop completely.
  • Running fast all the time are junk miles. Everything at the same hard pace will cause overtraining even more than a high milage training schedule. A variety of workouts is needed to achieve best results.
  • Running slow all the time are junk miles. A combination of both fast and slow running often produce the best results.
  • Running hills incorrectly in key sessions are junk miles because you will not achieve the optimal training stress of the workout.
  • Junk miles do not exist when tapering. In this case, its not what you do that makes you stronger, its what you don’t do.
  • Speed work that is too slow is junk miles. When doing speed work, you might as well do it at the pace that will yield more results.
  • Returning to training too soon after racing are junk miles. This is similar to tapering in what you don’t do makes you stronger.
  • Participating in races too often are junk miles (or in this case junk racing).
  • Running an easy mile after a hard workout to cool down are not junk miles. Although you may think otherwise, if there was a clear purpose for running this extra distance then it should not be considered junk.

Junk Miles Vs Happiness Miles

If you run for enjoyment there is no such thing as a junk mile. While running long and slow may not be the best option from a performance point of view, in doing so you will maximize the time you are out there running which will increase your happiness and enjoyment. Junk miles can also be happiness miles.

Junk Miles and Your Training

It’s possible to over analyze many aspects of running and junk miles is a perfect example. Instead of using single definition and trying to eliminate bad workouts, instead make a more relaxed and flexible approach by using the above dot points.

Running should not be so strict that you need to eliminate all junk miles from your training. A certain element of enjoyment and running for the sake of running should exist in your training schedule. Your goal should be to progressively improve rather than attempt to eliminate junk miles and try to improve on every workout. Remember that races are for proving points, not workouts.

At the same time, identifying junk miles can be valuable if you want to improve but are being lazy by running all your workouts well below pace. Ultimately, you should aim to run with good form, fit in your key sessions, have a mixed amount training volume and training stress, only run as much as you can safely handle and have fun when training.