Home › Guides › Sessions and training

Can you do zone 2 training indoors?

Updated 2026-10-23 · Sessions and training

What zone 2 is meant to be

Zone 2 is steady aerobic riding, usually around 56 to 75 per cent of FTP. In practice: you can hold a full conversation, your breathing is deeper than resting but comfortable, and you could keep going considerably longer than you are going to.

It is the foundation most endurance training is built on, and the thing most amateur riders do least of, because it feels like it cannot possibly be doing anything.

Indoors it has one real advantage: no coasting. An outdoor zone 2 ride includes descents and junctions where you produce nothing. An indoor hour is a genuine hour of steady aerobic work, which is why indoor zone 2 sessions can be meaningfully shorter than their outdoor equivalents.

The discipline problem

Outdoors, the terrain keeps you honest in both directions. Indoors there is nothing to stop you creeping up, and three things that encourage it:

1. Boredom. Riding harder is more interesting, and the clock moves faster.
2. No feedback. Nothing tells you that you have drifted up except a number you may not be watching.
3. It feels unproductive. Easy riding on a turbo feels like you are wasting an evening, so you push.

The result is the classic amateur week where every session is moderately hard, nothing is easy, nothing is really hard, and progress stalls.

Keeping it honest

• Use ERG mode and set it low. The single most effective trick: the trainer simply will not let you ride harder. See what ERG mode is.
• Set an upper power limit, not a target, and treat going over it as a mistake.
• Use the talk test. If you cannot speak a full sentence comfortably, you are above zone 2.
• Watch something. This is the one session type where passive entertainment genuinely works, because you do not need to concentrate.
• Accept that it is dull. It is supposed to be. If every session is interesting, you are probably riding too hard too often.

How long, and how often

Because there is no coasting, 60 to 90 minutes indoors does the job of a rather longer outdoor ride. Even 45 minutes is useful if that is what you have.

For most people with limited time, one or two easy sessions a week alongside one or two harder ones is a sound structure. If you have more time, add it here rather than adding more intensity.

There is a long-running argument about how much low-intensity riding amateurs with six hours a week should do, and no web page can settle it. What is not controversial is that most amateurs ride their easy days too hard, and the turbo makes that easier than ever.