Zone 2 training and Sleep architecture
Each entry’s own grades, side by side. A grade says how strong the evidence is for one outcome — it does not rank one entry over the other.
Compound or practice
Zone 2 training
The unglamorous aerobic base that moves resting HR, mitochondria, and long-term health risk more than anything else per hour.
Grade A4 graded outcomesrevised Jun 22, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Compound or practice
Sleep architecture
The recovery system everything else compounds on — deep and REM timing matter more than raw hours.
Grade A4 graded outcomesrevised Jun 28, 2026
A hand-written entry in Prometheus's bundled library. Its grades are the entry's own reading of the evidence, not a peer-reviewed review.
Graded in both
Outcomes are matched by name. Two entries can describe the same outcome in different words, so one listed further down may still be graded in the other.
No outcome has the same name in both entries. They may still overlap under different wording — read the two lists below.
Graded only in Zone 2 training
- Resting heart rate Moderate effectEvidence grade A
- VO₂max (untrained→trained) Large effectEvidence grade A
- Fat oxidation capacity Moderate effectEvidence grade A
- All-cause mortality (cohort) Large effectEvidence grade B
Graded only in Sleep architecture
- Insomnia severity (CBT-I components) Large effectEvidence grade A
- Deep-sleep minutes (schedule consistency) Moderate effectEvidence grade A
- Next-day cognition Moderate effectEvidence grade A
- REM cost of evening alcohol Moderate effectEvidence grade A
Conditions
- HypertensionZone 2 training: ImprovesEvidence grade ASleep architecture: ImprovesEvidence grade B
- Type 2 diabetesZone 2 training: ImprovesEvidence grade ASleep architecture: ImprovesEvidence grade B
- DepressionZone 2 training: ImprovesEvidence grade BSleep architecture: ImprovesEvidence grade B
Only in Zone 2 training
- Knee osteoarthritis May improveEvidence grade B
Only in Sleep architecture
- Insomnia ImprovesEvidence grade A
What each entry says about the other
Neither entry records anything about the other. That is not evidence that they do not interact — only that neither entry says.
Both columns are read from the entries as they stand in this library. A comparison is not advice to take either one, and it is no substitute for a clinician who knows the person.