---
title: Beware of the Gray Zone Where Junk Miles Live
modified: 2026-06-10
tags: []
---

A junk mile is a run done at a moderate intensity, typically 70–85% of your max heart rate. The gray zone—where junk miles live—is _neither easy enough to promote recovery nor hard enough to drive meaningful adaptation_. Spending too much time here can lead to stagnation, increased fatigue, and a higher risk of injury.

# How to identify junk miles?

## Test 1: The Heart Rate Test

If you wear a monitor, check your average heart rate during the run.

* True easy running sits at 60 to 70% of max HR, around 120 to 140 bpm depending on fitness and age.
* True hard running sits at 85 to 95% max HR, around 160 to 180 bpm.

> [!WARNING] If your easy runs are landing at 75 to 82% max HR, you’re in the moderate zone.

> [!WARNING] If your workouts aren’t designed around a specific pace or threshold target, they’re probably moderate-intensity junk.

## Test 2: The Talk Test

* During the easy run, you should be able to speak in full sentences.
* At hard pace, you should be able to speak only a few words at a time before gasping.

> [!WARNING] If your easy runs require conscious effort or feel more like a workout than relaxed movement, you’re running at a moderate intensity and not getting the recovery benefits you need.

> [!WARNING] If you’re at a pace where you can speak but feel like you need to take breaths between phrases, you’re in the moderate zone.

# References

* [What Are Junk Miles in Running? (And Why You’re Probably Getting It Wrong)](https://runnersconnect.net/what-are-junk-miles-in-running/)