For decades, coaches and lifters have measured strength with a simple piece of arithmetic: divide the weight on the bar by the athlete’s bodyweight, and compare the result against a fixed milestone. The double-bodyweight squat and the triple-bodyweight deadlift have become badges of honor in gyms around the world, shorthand for athletic status that requires no software, no calculator, and no explanation. A new analysis of more than 100,000 competitive powerlifters, however, shows that this beloved heuristic rests on a faulty assumption, and the authors have replaced it with something far more rigorous: percentile-based normative standards that account for the way human strength actually scales with body mass.
The study, published in Sports Medicine – Open, was led by Simone Montenegro of the German Sport University Cologne, together with Pamela Wicker, Tim Wiedenmann, Ludwig Rappelt and Lars Donath. The team drew on the Open Powerlifting database, restricting their sample to drug-tested, unequipped “classic” powerlifting competitions sanctioned by the International Powerlifting Federation and its national affiliates between January 2015 and March 2026. To ensure a homogeneous contemporary population, they limited analysis to full-power results comprising the squat, bench press and deadlift, and to athletes aged 21 to 49 years, a window designed to encompass the age of peak competitive performance in the sport, reported at roughly 27 years.
A crucial methodological decision shaped everything that followed. Large athletic databases are noisy: a single athlete may appear dozens of times, and most of those entries capture sub-maximal performances rather than career-best efforts. To solve this, the researchers applied what they call a “Best-Ever” filter. Each unique athlete was linked by name and sex, and only the single competition containing their highest recorded total was retained. Anchoring on the best-total competition, rather than stitching together best lifts from separate events, preserved the internal coherence of the three lifts as one simultaneously achieved performance. The final sample comprised 101,898 athletes, of whom 67,789 were male and 34,109 were female.
The statistical engine of the study was quantile regression, a technique that estimates specific points of the performance distribution, in this case the 50th, 75th, 90th and 99th percentiles, independently, rather than focusing only on the average lifter. Standard errors and confidence intervals were derived through bootstrap resampling to ensure robust inference at the extreme quantiles, and the researchers labeled the four tiers Intermediate, Advanced, Elite and World Class, following terminology common in strength and conditioning practice. The analytical unit was the bodyweight multiplier, the ratio of load lifted to body mass, but the authors were explicit that the ratio served as a diagnostic tool, not a benchmark: the entire point was to test whether a single fixed multiplier could mean the same thing across the body-mass spectrum.
It cannot. The analysis revealed a highly significant, systematic, non-linear decline in relative strength with increasing body mass across all lifts, all percentiles and both sexes. The most striking illustration comes from the male world-class tier: the smoothed 99th-percentile deadlift multiplier fell from 4.37 times bodyweight in the 59-kilogram class to just 2.65 times bodyweight in the 120-plus-kilogram category. In other words, a numerical standard that an elite lightweight could achieve comfortably sits at the absolute frontier of what an elite super-heavyweight can manage. The decay coefficients are small but relentless, and the researchers quantify their meaning precisely: a coefficient of -0.01 means that for every 10 kilograms of additional body mass, an athlete’s expected multiplier drops by exactly 0.1 times, for instance sliding from a 2.1-times to a 2.0-times squat.
Perhaps the most novel finding is that this decline is not uniform across skill levels. Pairwise comparisons of the quantile slopes, conducted with Wald tests for equality of coefficients, confirmed that the rate of relative-strength decay becomes significantly steeper as performance level rises. World-class athletes at the 99th percentile lose relative strength with each kilogram of body mass considerably faster than intermediate lifters at the 50th percentile. The authors suggest a likely explanation rooted in training physiology: muscle hypertrophy follows a linear-log trajectory, so advanced lifters experience diminishing returns in muscle accretion. When elite athletes gain weight, a larger proportion of that new mass may be non-contractile tissue, bone, connective tissue and fat, that inflates the denominator of the strength-to-mass ratio without contributing to the force-producing numerator.
This mechanism connects back to one of biology’s oldest mathematical constraints, the Square-Cube Law. As a body scales up, its mass increases with the cube of its linear dimensions, while the cross-sectional area of muscle, the tissue that actually generates force, increases only with the square. Heavier athletes are therefore structurally constrained to lower strength-to-mass ratios than lighter athletes of equivalent training status, a principle long established in the biomechanics literature. The observed declines in this dataset often exceed the theoretical predictions of pure geometric scaling, and the authors point to the fat-free mass index ceiling as a contributing factor: as lifters approach their natural hypertrophic potential, further mass gain becomes progressively less functional.
The study also documented a systematic shift in what the authors call the internal lift ratio, the percentage contribution of each lift to the competitive total. In the lightest weight classes, the deadlift dominates, contributing roughly 42 to 45 percent of the total. As body mass increases, that dominance erodes: in the heaviest male categories, the gap between deadlift and squat contribution narrows from an eight-percentage-point difference to roughly two points, at approximately 39 versus 37 percent. Regression models indicated that each 10-kilogram increase in body mass is associated with about a 0.44 percentage-point reduction in the deadlift’s share and a 0.28 percentage-point increase in the squat’s share. The likely culprit is soft tissue interference: greater abdominal and thigh girth can compromise the deadlift starting position or lockout, while added body volume may assist the squat through passive joint stability and a reduced effective range of motion.
Sex differences added another layer of complexity. Female athletes exhibited a steeper mass-dependent decline in bench press and squat performance than males. At the 99th percentile, the female squat decay coefficient was -0.0136 against the male -0.0125, meaning that for every 10 kilograms of body mass, a world-class female lifter loses 0.136 times bodyweight in relative squat strength compared with 0.125 for her male counterpart. The female bench press proportion of the total remained essentially static across the mass spectrum. The authors note this upper-body discrepancy may reflect both biological differences in regional muscle distribution and sociological factors, such as lower prior exposure to upper-body training among women, citing meta-analytic evidence that females make larger relative upper-body strength gains in response to training. The practical implication is blunt: applying male-derived multipliers to female athletes sets targets that simply do not correspond to the observed female performance distribution.
To make the findings usable on the gym floor, the researchers converted their statistical models into absolute-load normative atlases, stratified by sex, lift and current IPF weight class, expressed in raw kilograms with no calculation required. A coach can now determine whether an 83-kilogram athlete’s 180-kilogram squat sits at the 50th or the 90th percentile of drug-tested competitors worldwide, and whether the deadlift and bench press sit at comparable percentiles, something no aggregate score like the Wilks or IPF Good Lift coefficient can reveal, since those formulas compress the three lifts into a single number optimized for cross-weight-class ranking. The atlases also offer an empirical anchor for weight-class transitions: because relative multipliers fall even when absolute strength is maintained, an elite athlete moving up a class faces a disproportionately steeper relative decline than an intermediate lifter making the same move. The authors caution that the atlases are current reference values rather than permanent benchmarks, noting that squat and deadlift medians can rise by roughly 2.5 to 7.5 kilograms within five-year periods, and recommend periodic re-derivation. They also acknowledge limitations, including weigh-in manipulation through weight cutting, the absence of anthropometric data such as limb lengths, and the possibility that name-based athlete matching allowed a small number of duplicate records. Still, the message to the strength community is clear: the era of one-size-fits-all bodyweight multipliers is over, and the data have finally caught up with the barbell.
Subject of Research: Percentile-based normative standards for assessing relative and absolute strength across body mass categories in competitive classic powerlifting
Article Title: Percentile-Based Normative Standards for Strength Assessment Beyond Linear Bodyweight Multipliers in Competitive Powerlifters
Article References: Montenegro, S., Wicker, P., Wiedenmann, T., Rappelt, L., & Donath, L. (2026). Percentile-Based Normative Standards for Strength Assessment Beyond Linear Bodyweight Multipliers in Competitive Powerlifters. Sports Medicine – Open, 12(1), Article 136. https://doi.org/10.1186/s40798-026-01111-z
Image Credits: AI Generated
DOI: 10.1186/s40798-026-01111-z
Keywords: powerlifting, bodyweight multipliers, normative standards, quantile regression, relative strength, squat, bench press, deadlift, weight classes, sexual dimorphism, strength and conditioning, IPF
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Tags: bench pressbodyweight multipliersdeadliftIPFnormative standardspowerliftingquantile regressionrelative strengthsexual dimorphismsquatstrength and conditioningweight classes
