Easy Run Training: Benefits, Pace Guide, and Heart Rate Zones

If you have started taking your running seriously, you have likely come across the term “easy pace” — also known as E pace, easy running, or recovery run.

This article covers easy run training — the single most important type of running in any endurance program, and the one runners spend the most time doing.

Even elite runners who compete on the world stage perform roughly 80% of their training volume at this easy intensity (below lactate threshold).※1

This 80% low-intensity / 20% high-intensity distribution is known as polarized training — an intensity distribution proven by RCTs (randomized controlled trials) to produce the greatest improvements in VO2 max and endurance performance.※2

Easy run training has its own distinct purpose, and understanding it allows you to get the maximum benefit by incorporating it intelligently into your program.

What Is Easy Run Training? (and Recovery Run)

Recovery-Favorable Intensity — The Defining Principle

In simple terms, easy run training is “running at an intensity where recovery outpaces the training stress.”

One practical benchmark: the day after an easy run, your body should feel less fatigued than it did on the day of the run.

That does not mean easy running is a “fatigue-removal” tool. If your goal is pure recovery, complete rest will always outperform even the easiest jog.

What makes easy running valuable is this: at this low intensity, fatigue trends downward — yet it remains possible to maintain or gradually build the aerobic adaptations your body has developed.

Aerobic capacity begins to erode the moment you stop training. Research shows that meaningful declines in VO2 max can emerge within 2–4 weeks of stopping.※3 Metabolic changes — such as a greater reliance on carbohydrates over fat — can appear in as little as 10 days of inactivity.※4

Easy running lets you prevent these regressions while still allowing your body to recover.

None of this is an argument against complete rest days. When accumulated fatigue is high, prioritizing recovery through complete rest can be the most effective path to long-term performance gains.

What matters for long-distance runners is the ability to accumulate consistent, moderately stressed training over an extended period — and easy run training is perfectly suited for exactly that.

Easy Run in Jack Daniels’ Running Formula and Advanced Marathoning

For recreational runners without formal coaching backgrounds, the term “easy” as a training concept most often comes from the book Jack Daniels’ Running Formula. The book calls this easy running (E pace) — sometimes shortened to “E pace” or just “Easy.”

Advanced Marathoning also features a similar concept called the “recovery run,” with essentially the same training purpose.

Intensity Definitions: VO2max%, HRmax%, and More

Running training intensity is classified as shown in Table 1 (adapted from Exercise Physiology by Powers and Howley).

Here is how easy running (recovery run) is defined in each book:

These definitions partially overlap with the intensity zones in the table above. Easy pace does not have a sharp numerical boundary — the definition varies depending on who is using the term.

The core principle is that your recovery should be outpacing the training stress. Within that range, you have some flexibility to adjust intensity based on how your body feels on any given day.

The Purpose and Benefits of Easy Running

Easy run training prioritizes recovery while still improving aerobic function. Here is a summary of its specific purposes and benefits.

Building Injury Resilience

High-intensity sessions — tempo runs, interval training, and long runs — place significant stress on the body. Jumping into hard workouts without a proper base dramatically increases the risk of injury.

Consistent easy running builds the structural resilience needed to handle harder workouts without breaking down. Think of it as “training to train.” For endurance athletes, staying healthy enough to keep training consistently is everything.

Developing Cardiac Strength and Stroke Volume

Stroke volume — the amount of blood the heart pumps with each beat — is maximized at approximately 60–70% of max heart rate.

At high intensities, heart rate climbs so fast that diastolic filling time (the window for blood to flow into the heart chambers) shortens, creating a ceiling on per-beat blood volume.

Easy pace (65–79% HRmax) sits precisely within this optimal zone, making it an unusually efficient cardiac stimulus.

Repeated maximal-stroke-volume contractions cause the ventricular walls to thicken and expand over time, eventually allowing more blood per beat at any given heart rate — a process commonly called cardiac enlargement. This is how easy running improves cardiac output over the long term.

Stimulating Angiogenesis (Capillary Growth)

Oxygen reaches active muscles through the capillary network. Larger arteries transport blood throughout the body, but at the tissue level, it is the capillaries that deliver oxygen directly into muscle fibers.

As training increases capillary density around muscle fibers, the rate of oxygen diffusion from capillary to fiber improves — meaning each muscle fiber can extract more oxygen per unit of time.

Capillaries develop gradually through consistent long-term training. Here is one example of what improved capillary density can achieve:

In previously untrained individuals who trained over 32 months, VO2 max increased substantially — driven primarily by gains in the arteriovenous oxygen difference.※

The primary driver of the improved arteriovenous oxygen difference is increased capillary density. As more capillaries surround each muscle fiber, the muscles extract more oxygen from each pass of blood — raising the arteriovenous oxygen difference.

Growing Mitochondrial Capacity

Mitochondria convert carbohydrates and fat into usable energy. Training increases both their size and functional output.

Low-intensity running — like jogging — is particularly effective at increasing mitochondrial volume (size and quantity). A larger mitochondrial pool means a greater capacity to convert fuel into energy, which translates directly into improved metabolic efficiency.

How to Run Easy: Pace, Heart Rate, and Perceived Effort

Here is a quick summary of how to implement easy run training:

To calculate your easy pace using the VDOT Calculator, refer to this article:

In my own training, I find the boundary sits around 74% HRmax. When I run easy sessions above that intensity, I often notice residual fatigue the following day.

When I keep it at or below 70% HRmax, recovery clearly accelerates. During phases where I prioritize structured workouts, I make sure my easy days stay firmly below 70% HRmax.

The 65–79% HRmax range is a reference guideline, not a rigid rule. Experiment to find the intensity at which your own body recovers fully.

The Most Common Mistake: Drifting Into Moderate Territory

The biggest pitfall in easy run training is unconsciously letting your intensity drift upward. The role of easy running is to deliver minimal aerobic stimulus while letting the body recover.

A common scenario: you set out to run easy, but without noticing, the pace creeps up — and the recovery benefit is lost entirely.

As noted above, my personal threshold sits around 74% HRmax. Going above it on what is supposed to be an easy day often leaves noticeable fatigue the following morning.

The next intensity level above easy is moderate running — and that should always be a deliberate choice, not something that happens by accident.

A mildly elevated easy session provides virtually no additional aerobic stimulus for trained runners — while costing recovery. Keep your easy days truly easy.

References

※1 Seiler S (2024) “It’s About the Long Game, Not Epic Workouts: Unpacking HIIT for Endurance Athletes” Applied Physiology, Nutrition, and Metabolism

※2 Stöggl T, Sperlich B (2014) “Polarized Training Has Greater Impact on Key Endurance Variables Than Threshold, High Intensity, or High Volume Training” Frontiers in Physiology

※3 Mujika I, Padilla S (2000) “Detraining: loss of training-induced physiological and performance adaptations. Part I: short term insufficient training stimulus” Sports Medicine

※4 Mujika I, Padilla S (2001) “Cardiorespiratory and metabolic characteristics of detraining in humans” Medicine & Science in Sports & Exercise