Easy endurance: why running slowly makes you run fast
Easy endurance is the comfortable pace, the one where you can speak in full sentences. It makes up 70 to 80% of a plan's volume, and it builds the base that quality sessions rely on. Here is how your AI coach frames it and why it steers it by heart rate rather than pace.
Last updated: 2026-09-19
What easy endurance builds
At low intensity the body develops its capillary network, mitochondrial density and the ability to use fat as fuel. These are the adaptations that let you hold a marathon, and that make quality sessions more productive.
It sits between 60 and 70% of VMA, or 65 to 75% of maximum heart rate. With a VMA of 15 km/h, that is a pace of 5:45 to 6:40 per kilometre: much slower than most runners think.
Why the coach steers it by heart rate
Easy pace varies with heat, terrain, fatigue and sleep. Heart rate says what the body is actually doing. The plan therefore sends easy runs to the watch with a target in percent of max HR, not in pace.
If your max HR is not known, the coach estimates it from your Garmin activities, tells you, and proposes to confirm it. It never invents it.
The most common mistake
Running easy runs too fast. The grey zone, between 75 and 85% of max HR, tires without building endurance and without stimulating threshold. It is mistake number one for runners who plateau despite high volume.
- 60 to 70% of VMA, 65 to 75% of max HR.
- Speaking in full sentences must stay possible.
- 70 to 80% of weekly volume.
The coach's weekly review spots easy runs done above target in Garmin activities and points them out. Slow down is the most frequent advice it gives, and the most effective.
Frequently asked questions
Do I really have to run that slowly?
Yes. Progress comes from the contrast between easy and hard sessions. An easy run at 80% of max HR is neither.
How do I know I am in easy endurance?
You can speak in full sentences, and your heart rate stays under 75% of your maximum. The watch shows it live if the plan's target is in HR.
Should a beginner walk?
Often, yes: if running slowly pushes HR above 75%, alternating walking and running keeps intensity in the right place. The restart plan builds it in.
Let your assistant write your sessions
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See the connection guide