Easy Run Pace: How Slow Should You Actually Run?

The first kilometre of an easy run should feel slightly embarrassing. If it looks respectable on the watch, I have usually already lost the session.

"Run easy" is the instruction people hear and then replace with "run comfortably." Reasonably comfortable, around here, is the grey zone. Too much fatigue for a recovery day, not sharp enough to count as the work you were saving the week for. After a few weeks of that, the interval morning arrives with legs that already did their shift.

What the slow day is for

It is not a fitness test. The point is to keep a low intensity going long enough that the aerobic work happens, and short enough, or easy enough, that the next hard day still exists.

Stephen Seiler and Espen Tønnessen kept landing on the same split in elite endurance training: about 80% of sessions clearly below lactate threshold, not in the middle people call honest. You do not need their athletes to use the idea. If the easy days are not easy, you do not have an 80% week. You have a week of medium, and then a workout you cannot hit. (Seiler & Tønnessen, 2009, Sportscience)

Jack Daniels puts easy running at roughly 59 to 74% of VO2max, and he keeps those runs somewhere between about 30 and 150 minutes. In practice that is a conversation, full sentences, not four words and a gasp. If you only have one number, use the slower half of your VDOT easy range, especially after the halfway point, and especially the day after something sharp. (Daniels, 2013)

A recent race in the easy run pace calculator, or the full set in the VDOT pace calculator, beats the rule of thumb I used to carry around. Easy often lands well slower than 5K pace. How much slower depends on the result, not on how fresh the first kilometre felt.

Talk, then the watch

On a flat path with no wind I will glance at the pace. Into the polder, or on the open stretch when the westerly is up, the split lies. Carl Foster's session-RPE is the correction I trust: the load is how hard the whole run felt, times how long you were out. A slow-looking 10 into a headwind can be a harder day than a calm 10 at the same number. If you cannot speak in full sentences, you are not on an easy run. Slow down. Walking a steep bit, or thirty seconds when the heat spikes your heart rate, keeps the effort where the session belongs. The watch is not the workout. (Foster et al., 2001, Journal of Strength and Conditioning Research)

Heart rate can help if you already know what easy looks like on your own strap. I would not chase a zone on a warm afternoon while the number drifts up and the pace stays the same. Ease off. The talk test does not have a firmware update.

Where I put those days

Familiar, flat if I can get it, few lights. A recovery morning does not need a tour. The running route planner or a loop from home is enough. The job is to finish the distance without making a decision every junction.

If the week itself is the missing piece, a plan that already separates the hard day from the volume is more useful than another pace debate. An 8-week 5K plan or a 10K plan for busy weeks will do that only if you actually run the easy days easy. When sleep or the week comes back heavier, the adjustments should move the target, not ask you to prove the number anyway.

Check the range before the next one, then start slower than the part of you that wants the first kilometre to look like training. Start a plan if you want that pace already on the day, including the morning the wind makes the honest version look silly.

Sources

Daniels, J. (2013). Daniels' Running Formula (3rd ed.). Human Kinetics.

Foster, C., Florhaug, J. A., Franklin, J., Gottschall, L., Hrovatin, L. A., Parker, S., Doleshal, P., & Dodge, C. (2001). A new approach to monitoring exercise training. Journal of Strength and Conditioning Research, 15(1), 109–115. https://doi.org/10.1519/00124278-200102000-00019

Seiler, S., & Tønnessen, E. (2009). Intervals, thresholds, and long slow distance: the role of intensity and duration in endurance training. Sportscience, 13, 32–53. https://www.sportsci.org/2009/ss.htm