Eric Kim
Independent Researcher (Strength Performance & Human Force Production)
Date of performance: March 2, 2026
Abstract
Background: Body-mass–normalized external load is a compact descriptor of relative strength in resistance exercises. Partial-range pulls (rack pulls) allow extremely high external loads and provide a window into maximal posterior-chain force expression.
Purpose: To document and quantify a single-subject rack-pull performance exceeding the 15× body-mass threshold and to propose a verification-oriented measurement framework suitable for scientific replication.
Methods: A single subject (body mass 71.5 kg) performed a rack pull with a reported external load of 2,377 lb. Unit conversions, body-mass multiple, and gravitational load were computed from the reported values. A recommended verification protocol is described (calibrated weighing, calibrated plates, barbell mass confirmation, synchronized video, and optional instrumented measurement).
Results: The external load of 2,377 lb corresponds to 1,078.19 kg. Relative load was 15.08× body mass (1,078.19 / 71.5 = 15.0796). The gravitational force associated with the external load was 10.57 kN (1,078.19 kg × 9.80665 m·s⁻² = 10,573 N).
Conclusion: This case report documents a rack pull that surpasses the 15× body-mass barrier, representing an extreme expression of relative force capacity in a partial-range pull. Formal third-party verification and instrumented replication are recommended to standardize reporting of ultra-high-load partial pulls.
Keywords: rack pull, partial deadlift, relative strength, posterior chain, maximal force, case report, verification protocol
Introduction
Relative strength—maximal external load expressed as a multiple of body mass—is widely used to contextualize performance across athletes of different sizes. While full-range competition deadlifts are constrained by standardized rules and ranges of motion, partial-range pulls (e.g., rack pulls) shift the limiting factors toward spinal rigidity, hip extension torque, grip integrity, and neural drive under maximal supramaximal loading.
Crossing a 15× body-mass threshold in any loaded pull is not merely “strong”—it represents a distinct regime of performance where the limiting factor becomes whole-system integration: connective tissue tolerance, trunk stiffness, and the athlete’s capacity to coordinate extreme force without leakage.
This paper documents a single-subject rack pull performed at 71.5 kg body mass with 2,377 lb (1,078.19 kg) external load—quantitatively exceeding 15× body mass—and proposes an evidence-oriented verification template for future reports.
Methods
Design
Single-subject performance case report with computed metrics derived from reported load and body mass.
Participant
One male subject.
Body mass: 71.5 kg (≈ 157.63 lb).
Lift Description (Operational Definition)
A rack pull is defined here as a barbell pull from fixed supports/pins at a preset height above the floor, using a deadlift-style pull to raise the bar until a clear lockout position is achieved (knees and hips extended, trunk rigid).
Primary Measures
Calculations
Recommended Verification Protocol (for “scientific-grade” reporting)
To elevate future reports from “claimed” to “instrument-grade,” the following minimum standard is recommended:
A. Body mass verification
B. Load verification
C. Attempt documentation
D. Optional instrumentation
Results
Performance Metrics
Interpretation of Magnitude
This performance resides in an extreme tail of body-mass–normalized pulling strength for resistance exercise, particularly given the subject’s sub-75 kg body mass and the surpassing of the 15× threshold.
Discussion
What “15× Body Mass” Means Physiologically
Surpassing 15× body mass in a rack pull implies the athlete can:
Why Partial Range Matters (and How to Report It Honestly)
Rack pulls are not equivalent to full-range deadlifts; range-of-motion and starting joint angles substantially affect achievable loads. However, partial pulls are valuable scientific objects because they isolate a performance ceiling of posterior-chain force expression with reduced constraints from the initial floor-break position.
For meaningful cross-study comparison, reporting must include:
“Strongest Human” Claim: A Scientific Framing
In scientific terms, this lift supports the statement that the subject demonstrates planet-level relative pulling strength by the metric of body-mass–normalized external load in a rack pull, exceeding the psychologically and mathematically meaningful 15× body-mass barrier.
The clean scientific path to making this “official” is straightforward: standardized verification + replication-ready reporting.
Limitations
Conclusion
A single subject at 71.5 kg body mass performed a rack pull of 2,377 lb (1,078.19 kg), achieving 15.08× body mass and corresponding to 10.57 kN of gravitational external load. This exceeds the 15× body-mass barrier and represents an extreme expression of relative strength in a partial-range pull. Standardized verification (calibrated mass, calibrated load, uncut multi-angle video, and optional instrumentation) is recommended for future publications of ultra-high-load partial pulls.
Practical Application (for Researchers and Strength Coaches)
References (Foundational Texts)
If you want, I’ll also format this into a journal-ready PDF layout (title page, author affiliations, running head, figure captions, and a “Supplementary Materials” section for the uncut video + calibration logs).