The longevity world's favourite training zone — and why the hype is mostly earned.
"Zone 2" has become one of the most talked-about training concepts in longevity and endurance circles — and unlike a lot of fitness trends, the underlying idea holds up well.
Zone 2 refers to a heart-rate range — roughly the effort at which you can still hold a conversation but not sing — that trains your aerobic base without accumulating much fatigue. A common rough marker is the pace at which you can breathe comfortably through your nose, though individual heart-rate zones vary and are best estimated from your own max heart rate or a lab test.
Because Zone 2 sessions are moderate rather than maximal, they can be done frequently — several times a week — without generating the recovery debt that harder interval sessions require. Consistent, moderate aerobic activity is one of the more reliably supported ways to lower chronic inflammatory markers over time, precisely because it's sustainable rather than sporadic.
Zone 2 builds aerobic capacity; it doesn't replace the benefits of strength training or occasional higher-intensity work. Most well-rounded routines include some of each.
How THE FAD scores it: steady, moderate movement contributes positively to your Exercise signal without the "recovery debt" flag that follows unrecovered high-intensity training.