Junk miles - is there such a thing?

No, not really. There is not doing enough speed and not getting enough recovery, but there aren't really pointless miles if you recover.

No.

Absolutely.

Yes junk milage is real.

Its called high mileage

It depends on what your purpose for running is. If you're just Forrest Gumping it, there's very little junk and "you just feel like running."

But if you're working towards any type of goal there certainly are junk miles; including those miles that aren't run with any purpose behind them or those that are just excessive and putting unnecessary stress and wear & tear on your body.

Rest in underrated.

It's an outdated term with no nuance (as they tend to be). There is a law of diminishing return with mileage, where running more is hurting more far more than it's helping you.

If you know why you're running the miles you're running, and why not running them is or creates a specific problem, then they're not junk.

I used to think junk miles were around marathon pace but now I agree with other posters that miles without purpose could fall under the category. It could be argued non race specific miles be junk as well if you are in a particular stage of training.

Perhaps once you're getting up above 130 miles/week, but in my experience, the people bandying around the term are low-mileage runners who would definitely benefit from some "junk miles".

These people seem blind to the fact that 99% of elite distance runners are running at least 90mpw, and the very best are doing well in excess of 100.

You can't run that much without doing a lot of easy miles.

There are 2 main categories of junk miles.

The first one is running far too slow. For example if you are a 14:50 5k runner but you run super hige mileage 120-140mpw and log a bunch of easy runs around 7:00/km pace at a heartrate that doesn't even reach zone 2. That is total junk mileage, it does nothing for you.

The second one is very common in people who have just started running. They will be in 20 minute 5k shape but think they need to run fast to get fast, so all their 'easy' runs will be done around 4:15-4:20/km. These are junk miles.

I think we are now having a discussion about whether training incorrectly is junk miles? Not sure that was the OP intent. Junk miles i thought was a concept of running at a pace that doesn't fall neatly into threshold or VO2 etc? Obviously junk miles exist if we define it as any training run that is not optimal for your goals on ay given day. Or a bad training plan.

But all paces have some benefit physiologically. If you run your threshold too slow you are practicing marathon pace. Too fast you might be practicing 5k pace. And of course your body doesn't ever work or stress anything one system100%.

IMO- Depends on the events. 5k and up require certain amounts of milage to be successful. 1500 and down any running that is added to a program in order to hit a specific weekly milage goal to me is junk milage. I get tired of of coaches prescribing milage goals to someone who is racing less than 2 mins and thinks they need weekly long runs and 8 mile recovery runs. Hard to get fast when you always train slow. (That is needed during certain phases, just not during race season)

I didn’t think junk miles were a thing. Doubled 4 x a week in college, 100 miles a week. Now I’m running faster at 75-80 a week on singles. Maybe they are a thing?

If you are running in Zone 2, those are junk miles

I view things like this as junk miles:

1.5 mile "shakeout" on a non-race day

Split cooldown: 1 mile, then 2 more miles a bit later

That is factually incorrect.

I'm not going to show my work. If you believe that's true, show yours. Give us some links.

"You can never run too slowly. But you can run too fast." Arthur Lydiard. Viren did some runs where his heart rate was below 90.

And also a bit of a stretch. I mean running at 10min/km is junk miles because you are walking not running. 7min/km is brisk walk as well.