Each term has its own page with a fuller definition, where it shows up in practice, related concepts, and (where applicable) a peer-reviewed reference. Terms with deeper coverage on the site (Performance Index, ACWR, Tru40) link through to the full article.
Term
Quick definition
1RM — One-Repetition Maximum
The maximum weight an athlete can lift for one complete repetition of an exercise — the standard strength benchmark.
ACWR — Acute:Chronic Workload Ratio
The ratio of an athlete's last 7 days of training load to their last 28 — a flag for fitness vs. fatigue drift.
CMJ — Countermovement Jump
A vertical jump preceded by a fast downward dip — the most-used field test for lower-body explosive power.
DSI — Dynamic Strength Index
Peak ballistic force (e.g. CMJ peak force) divided by peak isometric force (IMTP) — a ratio of explosive to maximum strength.
EUR — Eccentric Utilization Ratio
Countermovement jump height divided by squat jump height — an index of stretch-shortening cycle contribution.
F-V Profile — Force-Velocity Profile
A linear regression of an athlete's force production across multiple loads — diagnoses force vs. velocity deficits.
HRV — Heart Rate Variability
The variation in time between heartbeats — a window into autonomic nervous system balance and recovery state.
IMTP — Isometric Mid-Thigh Pull
A maximal isometric pull from a static mid-thigh position on a force plate — a benchmark for peak force production.
MSS — Maximum Sprint Speed
The asymptotic top speed an athlete approaches in a sprint — the velocity ceiling fitted from sprint splits.
Performance Index
A composite 1–99 score combining six athletic qualities (speed, acceleration, agility, jump, power, strength) into one number.
Periodization
Systematic variation of training load and focus over time — splitting a season into phases with specific physiological goals.
PlayerLoad
A GPS/accelerometer-derived load score combining acceleration in all three axes — the standard external-load metric in team sport.
RSI — Reactive Strength Index
Jump height divided by ground-contact time — measures how efficiently an athlete converts eccentric pre-load into concentric output.
RTP — Return to Play
The structured process and criteria for clearing an athlete to resume full training and competition after injury.
SJ — Squat Jump
A vertical jump from a static squat hold — measures concentric explosive power without the stretch-shortening cycle.
sRPE — Session-RPE
A 1–10 rating of perceived exertion for an entire training session — the standard subjective load metric in team sport.
TRIMP — Training Impulse
A heart-rate-based training load measure — duration weighted by intensity to give a single "impulse" number.
Tru40
A sprint-model conversion that turns any sprint split (10–40, flying-10, etc.) into an equivalent 40-yard dash time.
VBT — Velocity-Based Training
Prescribing strength-training load by the bar velocity an athlete needs to maintain, not a fixed % of 1RM.
VO2max
The maximum rate at which the body can take in and use oxygen during intense exercise — the ceiling of aerobic capacity.
About this glossary
Written and maintained by Performance House. Term selection is biased toward the metrics that actually show up in modern athlete-management software and sport-science literature — the terms a working S&C coach encounters most often in published research, on force-plate readouts, and in load-monitoring dashboards.
Spot something missing or out of date? Email a suggestion and we'll consider it for the next batch.