Metrics Guide
Learn what each metric means, why it matters, and how it applies to your sport. Every number tells a story about your strength and performance.
Strength
1 metric
Max Force
kgWhat it is
The peak force you produced during the effort. This is the single highest point on your force-time curve.
Why it matters
The most fundamental measure of strength. Track it over time to see if you are getting stronger, compare sessions, and set benchmarks.
A climber pulls 45.2 kg on a one-arm hang test. Two months later they hit 49.8 kg — an improvement they can quantify.
Speed & Explosiveness
4 metrics
Time to Max
secWhat it is
How long it took you to reach your peak force from the start of the effort.
Why it matters
Faster times mean quicker muscle activation. Critical for sports where you need to produce force in a fraction of a second.
A sprinter reaches max force in 0.18 s while a recreational athlete takes 0.45 s — the difference matters at the starting blocks.
RFD Peak
kg/sWhat it is
The highest instantaneous rate of force increase within the first 200 ms. Your best single explosive burst.
Why it matters
Shows your maximum explosive potential — the fastest you can ramp up force. Used internationally in performance labs.
RFD 200ms
kg/sWhat it is
Average rate of force increase during the first 200 milliseconds.
Why it matters
A more stable measure of explosiveness than RFD Peak because it averages over a window. Ideal for tracking progress across sessions.
Comparing RFD 200ms before and after a plyometric training block reveals whether explosive capacity improved.
RFD 100ms
kg/sWhat it is
Average rate of force increase during the first 100 milliseconds.
Why it matters
Captures the very earliest neural activation — how fast your nervous system fires your muscles in the first tenth of a second.
Impulse
3 metrics
Impulse 0-300ms
kg·sWhat it is
Total force accumulated in the first 300 milliseconds of the effort (area under the force-time curve up to 300 ms).
Why it matters
Reflects your early force output in a time window relevant to jump takeoffs, punch contact, and sprint push-off.
Impulse 0-1s
kg·sWhat it is
Total force accumulated in the first second of the effort.
Why it matters
Gives a complete picture of your initial effort, combining both how much force you produced and how quickly you built it up.
Accumulated Impulse
kg·sWhat it is
Total impulse across the entire effort duration — the full area under your force-time curve.
Why it matters
Measures your overall work output. Higher values mean more total force sustained over time. Important for endurance-based strength.
Endurance
2 metrics
Stable 3s
kg + CV%What it is
The average force during the most stable 3-second window of your effort, plus the coefficient of variation (CV%) measuring consistency.
Why it matters
A low CV% means you held a steady output — important for rehab assessments and endurance benchmarks. The mean force shows your sustained capacity.
CV% below 5% is excellent consistency. Between 5-10% is good. Above 10% indicates variable output.
Average 5s / 10s / 20s / 30s
kgWhat it is
Average force you maintained over different time windows (5, 10, 20, and 30 seconds).
Why it matters
Shows how well you sustain force over increasing durations. Comparing across windows reveals your endurance profile — some athletes are explosive but fade quickly, others maintain well.
Analysis
3 metrics
Force-Time Curve
graphWhat it is
Your full effort plotted as force (vertical) against time (horizontal). Shows every phase: ramp-up, peak, plateau, and fatigue.
Why it matters
The most complete view of your effort. Coaches use it to identify technique issues, compare left vs right, and spot fatigue patterns.
Force-Duration Curve
graphWhat it is
The same data rearranged: force values sorted from highest to lowest, plotted against cumulative duration.
Why it matters
A flatter curve means better force endurance — you stayed near your max for longer. A steep drop-off signals rapid fatigue.
Effort Duration
secWhat it is
The total time of the test from start to end of meaningful force output.
Why it matters
Ensures consistency between measurements. If one test lasted 5 s and another 15 s, comparing other metrics directly may be misleading.
Balance
1 metric
Bilateral Symmetry
%What it is
Compares the max force between your left and right sides. 100% means perfectly balanced; lower values indicate a stronger side.
Why it matters
Identifies imbalances that could lead to injury or limit performance. Guides targeted training to bring the weaker side up.
A footballer shows 87% symmetry — the left leg produces 13% less force. Targeted single-leg work can close the gap.
Progress
1 metric
Progress %
%What it is
The percentage change in max force compared to your previous measurement of the same exercise and side.
Why it matters
Instant feedback on whether your training is working. Positive values mean you improved, negative means you declined.
Advanced
1 metric
EMIF
kg + rangeWhat it is
Estimated Maximum Isometric Force — your true max extrapolated from mathematical modeling of the force-time curve, including a confidence range.
Why it matters
In a real test you may not reach your absolute max. EMIF estimates what that ceiling is, giving coaches and researchers a more precise strength benchmark.
Measured max is 62.3 kg but EMIF estimates 67.1 kg (range 64.8–69.4). This suggests room to improve technique to unlock more force.