The hardest training isn't always the most effective. A large share of the benefit lies in training easily enough to talk, but often enough.
Reading time 6 min · Updated April 2026 · Aevia Insights
- Zone 2 is moderate intensity where you can still hold a conversation.
- It builds mitochondria and the aerobic foundation everything else rests on.
- 2–3 sessions a week of 30–60 min is enough for most people.
- Combined with a few hard intervals, it raises VO2max effectively.
What is Zone 2?
Zone 2 is an intensity where the body mainly burns fat and works aerobically, typically around 60–70% of your maximum heart rate. The rule of thumb: you can speak in full sentences, but not sing.
Why it works
Zone 2 increases the number and efficiency of your mitochondria, the cells' power plants. It improves fat burning, insulin sensitivity and endurance, and it's the foundation your hard intervals build on.
How much do you need?
- 2–3 easy sessions a week
- 30–60 minutes each
- Add one hard interval session weekly
The typical mistake
Most busy exercisers train in a "grey zone", too hard to be easy, too easy to be intervals. The result is fatigue without progress. The discipline lies in holding back.
Frequently asked questions
How do I know I'm in Zone 2?
The talk test is simplest: if you can speak in full sentences without gasping, you're there. A heart-rate monitor or a lab test makes it more precise.
Does a brisk walk count?
For the untrained, yes. If you're reasonably fit, reaching Zone 2 often takes brisk cycling, jogging or uphill walking.
This article is general information and does not replace individual medical advice.