A 2025 review finds no support for zone 2 as the best intensity for the general public
Is zone 2 training overrated?
The finding
The evidence does not support zone 2 as the best intensity for mitochondrial or fat-oxidation gains in the general public. Higher intensities matter more when total training time is low.
- Authors
- Storoschuk KL, Moran-MacDonald A, Gibala MJ, Gurd BJ
- Published
- Sports Medicine 55(7):1611–1624 · 2025
- Evidence
- Read in the primary source; numbers checked.
- Source
- doi.org/10.1007/s40279-025-02261-y
How it was studied
Narrative review of the evidence for zone 2 training and mitochondrial and fat-oxidation adaptations.
The numbers
The review says the case for zone 2 rests largely on observational data from elite endurance athletes who train at high volume.
What it does not show
A narrative review, not a meta-analysis. One author declares equity in an exercise-related company.
What Longstanding does with it
Zone 2 minutes are one of ten tests, measured against a weekly guideline. The app does not tell you zone 2 is the best way to train.