Performance Science
Performance Glossary
20 terms. Definitions written for practitioners, not textbooks — with optimal ranges, how to measure, and what to actually do with the information.
Wearables & HRV
Training Science
VO2 Max
Max oxygen consumption. The single strongest predictor of all-cause mortality in the literature.
Zone 2 TrainingZone 2
Aerobic exercise below the lactate threshold. The primary trigger for mitochondrial biogenesis.
Rate of Perceived ExertionRPE
Subjective 1–10 effort scale. Enables HRV-guided autoregulation of training intensity.
Lactate ThresholdLT
The intensity ceiling of Zone 2. Where aerobic metabolism gives way to anaerobic.
Progressive Overload
The systematic increase of training stress over time. The foundational principle of strength adaptation.
Deload Week
Planned volume reduction every 4–6 weeks. When the adaptations from prior training consolidate.
Mitochondrial Biogenesis
The creation of new mitochondria. The physiological basis for Zone 2 long-term effectiveness.
Nervous System
Autonomic Nervous SystemANS
Controls involuntary functions. The sympathetic/parasympathetic balance is the substrate of resilience.
Parasympathetic Nervous System
"Rest and digest." High parasympathetic tone at rest is the signature of high fitness.
Cortisol Awakening ResponseCAR
The natural cortisol spike 30–45 min after waking. The biological basis for morning peak performance.
Recovery
Deep Sleep (Slow-Wave Sleep)SWS
Stage 3 NREM sleep. When growth hormone releases and physical restoration peaks.
REM SleepREM
Memory consolidation, emotional processing, creative insight. Suppressed by alcohol.
Sleep Architecture
The pattern of sleep stages through the night. Total hours are a crude proxy for actual recovery.
Circadian Rhythm
Your 24-hour biological clock. Disruption impairs testosterone, metabolism, and cognition.
Longevity