What is easy pace, and why do most runners run it too fast?
Easy pace sits below LT1 — conversational, sustainable, and for most runners noticeably slower than the pace they habitually run on easy days.
Easy running has a physiological definition: below the first lactate threshold, around 65–75% of heart-rate reserve. In practice that means you can hold a conversation in full sentences. If you can only manage a few words at a time, you are above LT1 and the run has stopped being easy regardless of what your plan called it.
Running easy days slightly too hard is probably the most common structural error in recreational distance training. It feels productive and it is not: the sessions are too hard to be pure aerobic development and too easy to drive threshold or VO₂max adaptation, and the accumulated fatigue quietly degrades the quality sessions that would have produced real gains.
The reason volume in this zone matters is that it develops the aerobic machinery — capillary density, mitochondrial content, fat oxidation, cardiac output — at very low injury and recovery cost. That is what lets you run more, and running more is what most improvement actually comes from.
Two practical checks. Use heart rate as a ceiling rather than a target, and remember that heat, altitude and fatigue all raise heart rate at a given pace, so on those days easy pace is legitimately slower. And use the talk test, which needs no device and does not drift.
Key numbers
| Intensity | <65–75% HRR | below LT1 |
|---|---|---|
| Share of weekly volume | ~80% | typical polarized or pyramidal build |
Work it out for yourself
Marathon periodization planner — See what happens to fitness and fatigue when easy volume gets squeezed.
Frequently asked questions
How slow should easy runs be?
Slow enough to hold a conversation, which for most runners is somewhere between 60 and 90 seconds per kilometre slower than marathon pace. If that feels absurdly slow, that is the usual reaction, and it is generally a sign the zone was being skipped.
Do slow runs make you a slow runner?
No. The evidence runs strongly the other way: elite distance runners spend roughly 80% of their training time at low intensity, and the volume they accumulate there is what supports the hard work that produces speed.
Sources
- Seiler (2010). What is best practice for training intensity and duration distribution in endurance athletes? International Journal of Sports Physiology and Performance.
- Stöggl & Sperlich (2015). The training intensity distribution among well-trained and elite endurance athletes. Frontiers in Physiology.
Related explainers
Glossary: LT1 (Lactate Threshold 1), TID (Training Intensity Distribution)