Protocol Glossary
Science-backed definitions for every term in your health data: plain English and the mechanism behind it.
Acute:Chronic Workload Ratio (ACWR)
The ratio that separates productive overload from injury risk
→ Read definitionAerobic Base
The accumulated low-intensity fitness that lets you work harder, longer, and recover faster.
→ Read definitionAerobic Threshold (AeT)
The Zone 2 ceiling: where fat starts ceding to carbohydrates
→ Read definitionAllostatic Load
Your total accumulated stress burden: the body cannot separate the sources
→ Read definitionAnaerobic Threshold (AT)
The intensity ceiling where fat fuel gives out
→ Read definitionATP-PCr System
The immediate, oxygen-free energy system that powers your first 10 to 15 seconds of maximal effort.
→ Read definitionBlock Periodization
A model that sequences training into blocks, each concentrated on one physical quality, to build toward a single peak.
→ Read definitionCO2 Tolerance
How much carbon dioxide your body can tolerate before the brain triggers an urgent need to breathe.
→ Read definitionConcurrent Training
The interference effect between strength and endurance training
→ Read definitionDeload Week
The planned reduction in training stress where adaptation actually lands
→ Read definitionDetraining
How fast your fitness actually disappears when you stop
→ Read definitionDOMS (Delayed Onset Muscle Soreness)
The 24 to 72 hour soreness signal after novel or hard training
→ Read definitionEPOC (Excess Post-Exercise Oxygen Consumption)
The temporary afterburn cost of hard training
→ Read definitionFunctional Movement
Training the fundamental movement patterns your body needs for daily life, not gym gimmicks.
→ Read definitionGlycolytic vs. Oxidative Energy Systems
Two major pathways your muscles use to make energy: one fast and glucose-fueled, the other slower and oxygen-fueled.
→ Read definitionHIIT (High-Intensity Interval Training)
Short bursts of hard effort for cardiovascular adaptation
→ Read definitionHormesis
The biological principle that small, controlled doses of stress trigger adaptive responses that make your body stronger and more resilient.
→ Read definitionHypertrophy
The structural enlargement of muscle fibers in response to training stress
→ Read definitionLactate Threshold
The intensity above which your pace becomes unsustainable
→ Read definitionLinear Periodization
A model that moves training from high volume and low intensity toward low volume and high intensity across phases, to peak strength once.
→ Read definitionMind-Muscle Connection
The conscious practice of focusing on and feeling a target muscle work during a lift, which changes how many fibers in that muscle activate.
→ Read definitionMitochondrial Biogenesis
Growing new mitochondria: the cellular adaptation that drives aerobic fitness
→ Read definitionMobility vs. Flexibility
Two different physical capacities people use interchangeably, and only one of them requires strength.
→ Read definitionMotor Unit Recruitment
How your nervous system scales force output
→ Read definitionMuscle Memory (Myonuclei)
Why returning to training after a break is faster than starting fresh
→ Read definitionMuscle Protein Synthesis (MPS)
The cellular process that builds and repairs muscle
→ Read definitionNasal Breathing
Breathing through your nose instead of your mouth, both at rest and during easy training.
→ Read definitionNeuromuscular Fatigue
When your nervous system, not your muscles, is the limiter
→ Read definitionOne-Rep Max (1RM)
The ceiling that calibrates everything else
→ Read definitionOvertraining Syndrome
When accumulated stress outpaces recovery for long enough to break the system
→ Read definitionPeriodization
The structured organization of training stress and recovery across time
→ Read definitionProgressive Overload
The principle that drives all adaptation: consistently increase the demand to keep improving
→ Read definitionRPE (Rate of Perceived Exertion)
Your body's internal intensity gauge
→ Read definitionSAID Principle
The principle that your body adapts specifically to the type, intensity, and pattern of stress placed on it, not to exercise in general.
→ Read definitionStrength-to-Weight Ratio
How much force you can produce relative to your own body mass
→ Read definitionSupercompensation
The overshoot above baseline that makes training produce fitness
→ Read definitionTempo Training
Controlling rep speed to change the training stimulus without changing the weight
→ Read definitionTraining Frequency
How often you train a given muscle group or movement pattern each week, independent of total volume or load.
→ Read definitionTraining Intensity
How heavy or hard a given set or session is relative to your maximum effort.
→ Read definitionTraining Load
The cumulative stress of your recent training
→ Read definitionTraining Volume
The total amount of work performed in training, most often counted as sets per muscle group or total load lifted.
→ Read definitionTRIMP (Training Impulse)
A single number for quantifying training stress
→ Read definitionUndulating Periodization
A training structure that rotates load and volume across sessions or weeks so you develop strength, size, and power at the same time.
→ Read definitionVO2 Max Training Zones
The five-zone system for turning oxygen uptake into a training prescription
→ Read definitionZone 2
Low-intensity cardio that builds the engine everything else runs on
→ Read definitionZone 5 Training
Maximum-effort intervals that raise your aerobic ceiling
→ Read definitionMore terms added regularly. Check back for new entries across all categories.
