| Term | Plain-language definition |
|---|---|
| Sleep efficiency | The percent of time in bed you’re actually asleep (higher is generally better). |
| Sleep latency | How long it takes you to fall asleep after lights out. |
| Circadian rhythm | Your internal “clock” that times sleepiness/alertness, hormones, and temperature over 24 hours. |
| Chronotype | Whether you’re naturally more of a morning or evening person. |
| Term | Plain-language definition |
|---|---|
| VO₂max | A measure of aerobic fitness: how much oxygen you can use at maximal effort. Higher is generally better. |
| Zone 2 | Easy-to-moderate aerobic effort where you can talk in full sentences; used to build endurance base. |
| RPE | Rate of Perceived Exertion: a simple “how hard was that?” scale (often 1–10). |
| Progressive overload | Gradually increasing training difficulty so your body has a reason to adapt. |
| Term | Plain-language definition |
|---|---|
| Insulin sensitivity | How effectively your body responds to insulin; higher sensitivity usually means better blood sugar control. |
| Ultra‑processed foods (UPF) | Industrial formulations often high in added sugar/salt/refined starches/fats and designed for hyper‑palatability. |
| Time‑restricted eating (TRE) | Eating within a daily window (e.g., 8–12 hours) and fasting the rest. |
| Term | Plain-language definition |
|---|---|
| HRV | Heart rate variability: beat-to-beat variation that can reflect autonomic balance and recovery (context dependent). |
| Downshift | A deliberate short practice that reduces physiological arousal (breathing, walk, relaxation). |
| Term | Plain-language definition |
|---|---|
| Social isolation | Low objective social contact/network size (what your calendar looks like). |
| Loneliness | Subjective feeling of disconnection (how it feels). |