08
N1 Performance Lab  ·  Article 08  ·  Jun 2026
Issue 08
Forensic Performance Report
JUMP HEIGHT
LIES TWICE
TWO WAYS. PODS TELLS YOU WHICH.
RIPLEY  ·  BADBY  ·  YOSHIDA  ·  DONAHUE
O
JH · JM · mRSI
S
CD · TTTO
D
ARBf · ARPf
P
SW
READ THE CURVE.
n1lab.ph/Article_08
The Problem
BRAKING RFD
DROPS FIRST.
JUMP HEIGHT
DROPS LAST.
BUT JH ALSO LIES.
Two ways — once via mass loss, once via strategy widening. PODS tells you which.
Braking RFD drops first. Jump height drops last. But jump height also lies. A07 proved Braking RFD falls 20–40% from baseline across 6 sessions while jump height stays flat or rises. A08 proves the metric it leads away from actively misleads in two specific, nameable ways.
2
Independent mechanisms that inflate jump height without any change in neuromuscular output.
4
PODS layers that separate them. Person → Outcome → Driver → Strategy.
0
Capacity gains in either mechanism. Same outcome number. Different causal story every time.
Mechanism 01 of 02
MASS LOSS
INFLATION
JH = TOV² ÷ 19.62
The formula is mass-agnostic. Takeoff velocity is the product of net propulsive impulse divided by body mass — but once velocity is computed, mass exits the calculation. A 1% drop in body mass at constant propulsive impulse produces approximately a 2% increase in jump height. The athlete is lighter. The formula reports higher. Nothing changed in the muscle.
LIGHTER IS NOT STRONGER.
THE FORMULA DOESN'T KNOW
THE DIFFERENCE.
Mass Loss Algebra Chart — A08
d=1.35
SW ↓ single match
Ripley 2025
d=0.67
JH ↑ same match
The lie
d=0.68
ARBf ↓ same match
Honest signal
Source: Ripley et al. 2025 · Badby et al. 2025 · Hawkin Dynamics CMJ
Mechanism 02 of 02
STRATEGY
WIDENING
A deeper, slower countermovement extends the propulsive window. More time to build impulse over larger displacement. The same jump height arrives via a longer, more effortful path — braking force falls while the movement lengthens to compensate.
Donahue et al. (2023, NCAA Division I female volleyball, n=11): in a no-arm-swing condition, jump height increased +8.0% (p=0.001, g=1.70) in 10 of 11 athletes — propulsive force potentiated with it (p=0.002). The test condition produced the number. Not a readiness change.
SAME JUMP HEIGHT.
SLOWER. DEEPER.
LESS FORCEFUL.
Strategy Two-Panel Chart — A08
+8.0%
JH from NAS strategy
Donahue 2023
+1.0%
JH from AS strategy
Non-significant
10/11
Athletes potentiated
NAS condition
g=1.70
Large effect size
Donahue 2023
Source: Donahue et al. 2023 · Yoshida et al. 2023 · Hawkin Dynamics CMJ
The Framework
THE PODS
PYRAMID
Ripley et al. (2025) applied the reading framework. PODS is the diagnostic, not the replacement. Four layers. One outcome. N1 applies PODS as the standard reading order on every test day.
Start at Person. End at Outcome. Never the reverse. The number at the top is the last thing to read.
P
PERSON
SW — System Weight / Body Mass
Body mass. Both lie paths trace through here. The invisible variable.
D
DRIVER
ARBf · ARPf — Avg Relative Force
Average relative force. The signal that doesn't lie.
S
STRATEGY
CD · TTTO — Movement Configuration
Can inflate JH with no capacity change.
O
OUTCOME
JH · JM · mRSI — The Lying Layer
Jump height sits here. It tells you what happened. Not why.
FOUR LAYERS. ONE OUTCOME. READ ALL OF THEM.
The Recovery Lie — Yoshida 2023
24H
Post-Exercise · JH at Baseline
Jump height had returned to baseline at 24 hours post high-intensity exercise. Braking rate of force development was still −0.84 SD below baseline at the same timepoint. Full neuromuscular recovery required 48–72 hours. The athlete was not recovered. Jump height said otherwise.
SHE WAS NEVER AT BASELINE.
HER JUMP HEIGHT WAS.
Recovery Timeline — Yoshida et al. 2023
0H
Immediate Post-HIE
JH: −0.40 SD  ·  Braking RFD: −1.10 SD
2H
Acute Phase
JH: −0.20 SD  ·  Braking RFD: −1.66 SD (nadir)
24H
The Lie Window
JH: 0.0 SD — BASELINE  ·  Braking RFD: −0.84 SD — still impaired
48H
Partial Recovery
JH: +0.30 SD  ·  Braking RFD: −0.55 SD — approaching baseline
72H
Full Neuromuscular Recovery
Braking RFD: −0.15 SD — near baseline
Source: Yoshida et al. 2023 · Effect size vs. baseline · Post high-intensity exercise
The Potentiation Lie — Donahue 2023
THE ARM SWING
MASKED IT.
NCAA Division I female volleyball athletes (n=11). In the no-arm-swing (NAS) condition, jump height increased +8.0% (p=0.001, g=1.70 large effect). 10 of 11 athletes showed this pattern. The arm-swing condition showed +1.0% — non-significant.
The protocol shift — not the neuromuscular state — produced the jump height change. The signal was the intervention. Not the athlete.
THE PROTOCOL FOUND
THE SIGNAL.
THE ARM SWING HID IT.
Strategy NAS vs AS Chart — A08
Jump Height — Protocol Comparison
NAS
+8.0%
AS
+1.0%
RSI-Modified
NAS
+15.2%
AS
+2.9%
Source: Donahue et al. 2023 · NCAA Division I Female Volleyball · n=11 · p=0.001
Methodology
THE NUMBER
IS WHAT
IT IS.
Bakhshinejad et al. (2025) confirmed verbal cues and motivational protocols do not bias jump height output at scale — the replication effect size was η²=0.015 vs 0.348 for the original claim. The number you measure is structurally stable. The problem is not measurement noise. The problem is reading only one layer.
The Rule
When Person changes and Driver falls — mechanism one. Rehydrate. Do not train.

When Strategy widens and Driver falls — mechanism two. Recovery is the prescription.

When neither changes — JH moved because capacity moved. That is the only reading that supports a training progression decision.
PODS Minimum Viable Dashboard
7 METRICS.
ALL FOUR LAYERS.
P
Person
SW — System Weight
1 metric. The denominator in every kinetic calculation.
O
Outcome
JH · JM · mRSI
2 metrics. The visible signal — and the one that lies.
D
Driver
ARBf · ARPf
2 metrics. The kinetic mechanism that doesn't lie.
S
Strategy
CD · TTTO
2 metrics. The fingerprint of fatigue and compensation.
Total: 7 metrics across 4 layers · Matches McMahon metric ceiling
Forward Hook
THE [ORGANIZATION]
DATA GAP
This article ships on external evidence only. The research is confirmed. The framework is established. What does not yet exist is a baseline for all four PODS layers measured from our own roster — in our competitive context, across our season.
Here is what collection requires. Here is what that data would resolve.
The N1 baseline for these four PODS layers in Philippine volleyball is being built. That data lands in a future issue. Frame as anticipation — not apology.
What We Need to Collect
01
System Weight — Pre and Post Match
Weigh-in protocol before and after each competitive block. SW delta triggers the Person-layer read.
02
NAS and AS Protocol Trials
Paired CMJ conditions in each session. Arm-swing and no-arm-swing. The delta isolates strategy contribution from neuromuscular contribution.
03
ARBf and ARPf Across Sessions
The Driver layer — tracked longitudinally. When JH rises, Driver tells you whether force production followed or stayed flat.
04
CD and TTTO Trends
The Strategy layer. Widening TTTO during high-load weeks is the compensation fingerprint. That signal must exist in our own data before we can act on it.
OH·A
MB·1
S·2
L·1
N1
Article 08  ·  Jun 2026
Ripley 2025 · Badby 2025
Yoshida 2023 · Donahue 2023
Names & affiliations protected
Person → Outcome → Driver → Strategy. The roster speaks four languages at once. Jump height is not wrong. It is incomplete — without the three layers beneath it. PODS closes the diagnostic loop every test day.
READ THE
CURVE.
Issue 09 →
The Asymmetry in the Curve
Asymmetry is the fifth. The leg that's lying to you is on one side of the plate.
Athlete identities and institutional affiliations protected across all published outputs
Data sources: Ripley et al. 2025 · Badby et al. 2025 · Yoshida et al. 2023 · Donahue et al. 2023 · Hawkin Dynamics CMJ
Force plate testing in the Philippines: N1 Performance Lab PH  ·  n1lab.ph/Article_08
→