Training Metrics Glossary
How Afitpilot calculates tonnage, volume, RPE, estimated 1RM, and session quality.
- Strength & Load
Tonnage (Load)
The total weight moved in a session — the simplest measure of mechanical stress placed on the body. Tonnage captures "how heavy was today?" in a single number.
- Strength & Load
Estimated 1-Rep Max (e1RM)
A mathematical estimate of the heaviest weight you could lift for a single repetition, derived from a submaximal set. It lets us track strength progress without you ever needing to actually max out.
- Strength & Load
Session RPE (sRPE)
A single 1-10 effort rating for an entire training session, recorded after the session ends. Unlike per-exercise RPE (which captures individual sets), sRPE rolls the whole session into one number — your subjective answer to "how hard was today, all-in?".
- Strength & Load
Arbitrary Units (AU)
The primary internal-load number for a session: sRPE multiplied by actual duration in minutes. AU produces one comparable load score across strength, endurance, mobility, and skill sessions — something tonnage cannot do because it only exists for sessions that lift external weight.
- Strength & Load
Weekly AU
The sum of sessionAU across all completed sessions in a calendar training week, optionally split by modality (Strength / Endurance / Mixed). Weekly AU is the primary unit Afitpilot uses to describe "how much load did you absorb this week" — replacing weekly tonnage as the headline weekly number.
- Strength & Load
Modality
The 3-bucket coarse classification we apply to every session: Strength, Endurance, or Mixed. Modality is what makes weekly AU a richer story than a single number — it tells you whether your week leaned barbell-heavy, aerobic, or hybrid.
- Strength & Load
EWMA Load Trend
An exponentially weighted moving average (EWMA) of weekly AU, computed nightly. Acute load uses a 7-day window; chronic load uses a 28-day window. The chart is descriptive only — it shows whether your load is rising, falling, or stable over the last 12 weeks.
- Volume & Work
Volume (Total Reps)
The total number of repetitions performed in a session, aggregated across all exercises. Volume is the most fundamental "how much work did you do?" metric.
- Volume & Work
Sets
A set is one continuous bout of exercise — the number of times you perform a group of consecutive reps before resting. Sets are the fundamental building block of every workout prescription.
- Volume & Work
Reps (Repetitions)
One complete movement cycle of an exercise — one squat down and up, one press up and down. Reps are the atomic unit of training volume.
- Intensity & Effort
RPE (Rate of Perceived Exertion)
A 1-10 self-reported scale measuring how hard a set felt. In strength training, RPE is anchored to "reps in reserve" (RIR): RPE 10 means you couldn't do another rep, RPE 8 means you had roughly 2 reps left, RPE 6 means about 4 reps in reserve.
- Intensity & Effort
RIR (Reps in Reserve)
The estimated number of additional repetitions you could have performed before reaching muscular failure. RIR is the inverse anchor for RPE: RIR 0 = RPE 10 (failure), RIR 2 = RPE 8, RIR 4 = RPE 6.
- Intensity & Effort
Effort Delta
The difference between your actual session RPE and the prescribed target RPE. A positive delta means the session felt harder than planned; negative means easier.
- Progress Tracking
Anchor Exercise
The single exercise in a session that best represents your strength output — automatically selected based on tonnage contribution, historical recurrence, and data quality (RPE availability, set count).
- Progress Tracking
Reference Points
Contextual comparison points that give meaning to your session numbers. A tonnage of 4,200 kg is meaningless in isolation — but "4% more than your 3-session average" tells a story.
- Quality & Trends
Adherence
The percentage of planned sessions that were actually completed. The simplest measure of whether you're following the plan.
- Quality & Trends
Volume Adherence
How closely your actual rep volume matched the planned prescription, expressed as a percentage. 100% means exact match; above means you did more, below means less.
- Quality & Trends
Load Adherence
How closely your actual tonnage matched the planned prescription, expressed as a percentage.
- Quality & Trends
Session Quality Trends
A composite assessment of your training trajectory based on effort delta trends and adherence trends over your last 6 completed sessions.
- Quality & Trends
Joint Stress Load
A per-exercise metadata rating (low / med / high) for each joint involved in a movement, aggregated across your weekly plan to reveal which joints are accumulating the most stress. Unlike tonnage or volume, joint stress is not calculated from what you lift — it's classified from the exercise itself.
- Progress Tracking
Periodization
The systematic organization of training into time blocks — macrocycles, mesocycles, and microcycles — each with a specific focus, intensity target, and volume plan. Periodization is how Afitpilot structures your entire training journey rather than treating each week as an isolated event.
- Readiness & Recovery
Readiness
The athlete's arrival state before training — how rested, sore, and mentally prepared you are when you walk in. Readiness is the third layer of Afitpilot's load model (alongside internal load and external load), capturing context that load metrics alone cannot.
- Readiness & Recovery
Hooper Index
A 5-35 readiness score that sums five 1-7 self-ratings: sleep quality, muscle soreness, fatigue, mood, and stress. Lower is better — 5 is "feel great on every axis," 35 is "every axis at its worst." Captured once per calendar day via the daily prompt.
Room for Improvement
No methodology is perfect. Here's what we know needs work and where each improvement stands. We'd rather be honest about our limitations than pretend they don't exist.
Room for Improvement →