What Are Junk Miles?

One person’s junk miles is another runner’s secret to success. Image via wikipedia

Whether we run 100 mile weeks or 35 mile weeks, we run a lot and when we run we believe that every mile, in fact every step, is in furtherance of our goal to become faster. Is it possible that some of the miles we run are doing us no good or worse, *gasp* making us slower? Could you, yes YOU, be logging junk miles?

If you’ve read enough about running or talked to enough serious runners, eventually you will come across the term junk miles. When the average person throws out the term, junk miles, it’s usually as a way of passing judgment on another runner’s training. “She’s not getting faster because she’s running all those junk miles.” Most of the time it’s not a useful phrase, because it assumes there is a universal definition of junk miles that applies to every runner. Guess what. There isn’t one. Junk for one person might not be junk for someone else. It depends on the runner, her training plan and her goals.

But if we shift the concept from a judgmental insult to a principle of training that we can apply to ourselves and our goals, it’s actually a very useful concept that can help us take our running to the next level.

Let’s take a look.

Finally, a simple definition.

Junk miles are miles that do not further your running goals or worse, inhibit your achievement of your running goals. Junk miles are counterproductive. That’s it! You’re not a bad person if you run your easy runs faster than someone else thinks you should. You’re not doomed to failure if you don’t run your tempos faster than the paces spit out by the McMillan calculator. Now let’s figure our how to know if some of the miles you are putting in are junk miles for you.

Step 1: Identify your long-term running goals.

To achieve anything we need to establish our goals. A long term goal might be to qualify for Boston within 4 years. This long term goal should be the primary answer to the question, “why do I spend all this time running?” It certainly does not need to be a time goal. Your long term goal might be to make running second nature or simply to see where the journey takes you. Whatever it is, you need to know what it is to achieve it and to ensure what you do today will be a productive step to get you there.

Step 2: Make a plan to achieve that goal.

Most of the time we create a training plan to achieve that big goal or to achieve intermediate goals on our way to that big goal. That’s the plan I’m talking about. So pick a plan, hire a coach or draft your own. But you need a plan if you want to ensure your runs are productive to achieving your goals.

Step 3: Understand the components of your plan.

Now that you have a training plan, to properly execute it, you need to know the purpose of each component of that plan. What is the purpose of the long runs? The interval workouts? The tempos? The rest days? These moderate runs? Why are they in your plan and how are they going to help you achieve your goal? This might necessitate you doing a little research or asking questions of your coach to understand the components of your plan. Here’s a quick and dirty guide to get you started:

rest days: To recover mentally and physically from training. To give your body and mind a break to prevent injury, burnout or overtraining.

recovery runs: To maintain running volume while allowing for recovery from hard workouts.

easy runs: to build aerobic capacity and to teach the body to burn fat as fuel. To maintain running volume without unnecessarily breaking the body down.

tempo runs: to build mental and physical strength and endurance. To learn mental toughness and the ability to focus at a higher intensity for a longer period of time. Some say to improve lactate threshold, but recent studies call this into question.

interval workouts: to build strength, speed, running economy and leg turn-over. To get the brain accustomed to running fast.

long runs: to build aerobic capacity, endurance and strength. To teach the body to burn fat as fuel. To build mental toughness and focus.

It's not a junk mile if it gets you where you want to go.
It’s not a junk mile if it gets you where you want to go.

Step 4: Only do runs that will help you achieve your long term running goals.

For most of us, that means to make sure our effort on any given run is in furtherance of the purpose of that run. That means do not run on prescribed rest days. That means to run our hard runs at the proper intensity for us given the conditions and to run our easy runs at a truly easy-to-us pace. McMillan can give us an easy range of paces in his calculator, but maybe easy for you is faster or slower. It doesn’t matter as long as the miles you are running further the purpose of your training.

And think about it: if your goal is to train hard but enjoy a lifelong love of running and you love to run at a moderate pace or you can’t stand running your tempos faster than marathon pace, then running “too fast” or “too slow” might be the right answer for you. It really does depend on what your goals are and what your strengths and weaknesses are as a runner. The only person capable of judging whether your miles are junk miles is you or someone equally invested in the achievement of your goals and equally familiar with your abilities.

What do you think about junk miles? What’s your definition? 

Salty Running boss and mother of 3 little ones with PRs of 3:10:15 (26.2), 1:25:59 (13.1) and 18:15 (5k). I love to write about running culture, mental training, and fitting in a serious running habit with the rest of a busy life.

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    1. I think it’s really rare that a runner runs junk miles. I think the biggest risk for junk miles is habitually running easy runs too fast so that quality runs are negatively affected or such that the runner becomes injured and training is interrupted.

    2. I completely agree. I love to run so I really don’t consider any running miles “junk”, even if they don’t have a specific purpose for training.

  1. I’m really glad you wrote the post this way – I have definitely felt judged I the past by the use of “junk miles” when the reality was that I had different goals than the person who was telling me I was running too much.

    My training right now is for an unknown, and I don’t consider anything I do to be junk miles because I need to learn how to run in every situation – when I’m tired, just after I ate, just after I ran two marathons… Everything. Running straight for 65+ days is such an unknown, that the best we can do with my training plan is a general progression of mileage.

    That being said, I take a rest day every week (whether I feel like it or not). I still have a speed work day (usually my shortest mileage day) and the rest of my runs are done at what I call “chatting pace.” For anyone else, much of my mileage would be junk, but it’s all about the time of my feet for me right now. And staying uninjured.

    And I think the most important thing, no matter what I am training for, is that I still enjoy each run (at least most if the time). That takes away junk status, always.

  2. I’m in the habit of running almost all of my miles as fast as I can. Sometimes I’ll run with friends who are slower just to keep my self in check. Then I talk their ears off because I’m doing an easy run.
    I need to work on tempo runs, track work etc. I think I’m at the point where I’m not going to improve much more on my own. I need to get with a program.

  3. Excellent topic. Underlying the term “junk miles” is the quantity versus quality debate that seems to exist among running coaches.

    Three years ago I began training to run my first half marathon. I wanted to be able to run the half marathon in under 2 hours and based on my 5K personal record at the time of 24:31, the running calculator gods told me that, sure, I could run a half marathon in under 2 hours . . . . . . . . provided I trained properly.

    I didn’t enjoy doing intervals or “hard miles.” So, I decided to adopt one of Hal Higdon’s full marathon training plans because it contained more miles than his half marathon training plans.

    I wanted a high quantity of miles to prepare me for the half marathon. My triathlete relatives told me that “you have to run slow to become fast.” They deemphasized speed work. Building aerobic capacity was where it was at. After all, my 5K PR proved that I already had sufficient speed to do a sub 2 half marathon. I just needed the aerobic capacity to make it last for 13.1 miles.

    But then I stumbled onto the web pages of running coaches Joe English and Dean Hebert. I watched their online videos about proper training for marathons. They said that running more miles will not make you faster if you aren’t running those miles at your goal marathon pace. They said the bulk of ones miles should be at goal marathon pace or faster.

    I swallowed what they said. In fact, I probably mis-interpreted what they said.

    I started turning most of my training runs into tests of how long I could run at a 8:40 minute/mile pace (this was my new goal half marathon pace).

    What happened? I got slightly injured about a month before my half marathon. I finished my race. But I didn’t meet my goal. I bonked half way through the race.

    Once I recovered from my injury, I went to the other extreme. I did tons of long, slow distance. And zero speed work. That fall I ran in two half marathons and finished them both well under 2 hours.

    But now I want to run my half marathons even faster. So, I try to do lots of “junk miles” and a reasonable amount of running at my goal half marathon pace or my goal 10K pace.

    Still, when I recently suffered a disappointing half marathon result, one of the runners in my running club said to me, “You might be running too many junk miles.”

    This quantity versus quality debate never ends, it seems.

    I appreciate this post because it draws attention to this important debate.