Protocol Glossary
Science-backed definitions for every term in your health data: plain English and the mechanism behind it.
ALT & AST (Liver Enzymes)
Your liver's distress signal in a blood draw
→ Read definitionAutonomic Nervous System (ANS)
The body’s automatic regulatory control system
→ Read definitionBaroreflex Sensitivity (BRS)
How quickly your body corrects blood pressure swings
→ Read definitionBreathing Rate Variability
The natural ebb and flow in your breathing rhythm, and what a flattened pattern can mean
→ Read definitionComplete Blood Count (CBC)
The standard blood panel that screens oxygen transport, immunity, and clotting in one draw
→ Read definitionContinuous Glucose Monitoring (CGM)
Real-time blood sugar dynamics on demand
→ Read definitionCortisol Awakening Response (CAR)
The first hormonal signal that sets your day
→ Read definitionCRP (C-Reactive Protein)
Your body's systemic inflammation signal
→ Read definitionFasting Glucose
Your baseline blood sugar after an overnight fast
→ Read definitionFasting Insulin
The single blood number that shows insulin resistance years before glucose does
→ Read definitionFerritin
Your iron storage tank, and an inflammation marker
→ Read definitionGGT (Gamma-Glutamyl Transferase)
The liver enzyme most sensitive to alcohol and metabolic stress
→ Read definitionGlucose Variability
How much your blood sugar swings across the day
→ Read definitionGrip Strength
A simple squeeze that predicts how well you'll age
→ Read definitionHeart Rate Reserve (HRR)
The usable range between rest and maximum effort
→ Read definitionHeart Rate Variability (HRV)
Your nervous system's daily readiness signal
→ Read definitionHemoglobin A1c (HbA1c)
A 3-month average of your blood sugar control
→ Read definitionHOMA-IR (Homeostatic Model Assessment of Insulin Resistance)
The earliest measurable signal of insulin dysfunction
→ Read definitionhs-Troponin (High-Sensitivity Cardiac Troponin)
The blood marker that detects damage to heart muscle itself, not just its risk factors
→ Read definitionIron Panel & Ferritin
Your iron storage and delivery system, measured in full
→ Read definitionLF/HF Ratio
A window into your autonomic nervous system balance
→ Read definitionMax Heart Rate (MHR)
The ceiling of your cardiovascular output
→ Read definitionMuscle Mass Index
How much lean muscle you carry relative to your height
→ Read definitionOmega-3 Index (EPA + DHA)
Your cell membrane fatty acid quality score
→ Read definitionOrthostatic Heart Rate Test
A 60-second morning recovery readiness check
→ Read definitionReadiness Score
Oura's daily verdict on your capacity for stress
→ Read definitionRecovery Score
Your body's readiness verdict after last night
→ Read definitionRespiratory Rate
Breaths per minute: your body's quiet early warning signal
→ Read definitionResting Heart Rate (RHR)
How hard your heart works when it doesn't have to
→ Read definitionRMSSD (Root Mean Square of Successive Differences)
The beat-to-beat calculation that powers your HRV score
→ Read definitionSDNN (Standard Deviation of NN Intervals)
The HRV metric Apple Watch uses, and why it reads higher than Oura
→ Read definitionSkin Temperature Deviation
Your body's overnight thermostat as a recovery signal
→ Read definitionSpO2 (Blood Oxygen Saturation)
The percentage of your red blood cells carrying oxygen
→ Read definitionStrain Score
Your daily cardiovascular load, accumulated
→ Read definitionSympathetic vs. Parasympathetic
The two-branch system behind every readiness metric
→ Read definitionTriglycerides
The most measured, most misunderstood number on your lipid panel
→ Read definitionUric Acid
A metabolic waste product that predicts more than gout
→ Read definitionVagal Tone
The strength of your parasympathetic recovery signal
→ Read definitionVO2 Max
The strongest single predictor of long-term health and longevity
→ Read definitionVO2 Max (Lab Protocol vs. Wearable Estimate)
Why your watch's VO2 max number and a lab test can tell two different stories
→ Read definitionMore terms added regularly. Check back for new entries across all categories.
