Women Gained More Bench Strength—Until Researchers Changed the Math
UPLIFT IRON CLUBThe 12-Week Experiment That Made Strength Gains Look Different
Two people can follow the same lifting plan, add similar amounts of muscle and still appear to make dramatically different progress when their results are presented as percentages. That is the central lesson from a 2026 resistance-training experiment comparing experienced men and women. The headline-grabbing difference was in the bench press: women improved their one-repetition maximum by 32.8 percent, while men improved by 19.9 percent. Those numbers are real findings from the trial, but they are not a verdict that one sex is inherently better at building strength. How a change is measured matters just as much as the change itself.
The researchers followed 22 men and 19 women, all with more than a year of lifting experience. Participants completed a supervised, progressive resistance program twice weekly for twelve weeks. Strength was assessed with one-repetition maximum tests, while muscle thickness was measured using ultrasound at the biceps and vastus lateralis, a large muscle on the outside of the thigh. That design let the team compare performance changes with a direct, if localized, measure of muscular growth. It also made the groups more relevant to regular gym-goers than a study involving only complete beginners.
Importantly, the experiment did not compare two entirely different workout philosophies. It examined how groups responded to the same broad training intervention and how the answer changed when the results were expressed in absolute units, relative percentages or statistical models accounting for starting values. A lifter beginning with a lighter bench press can post a larger percentage increase without adding more weight to the bar than somebody who started stronger. That is not a statistical trick; it is the unavoidable arithmetic of different baselines.
Before treating these results as universal rules, remember the scale. Forty-one participants and twelve weeks can reveal useful patterns, but they cannot settle every question about age, training history, exercise choice or elite performance. The study also measured thickness in two muscle regions, not every muscle in the body. The sensible takeaway is more practical than competitive: compare progress against an appropriate starting point, and use several measures rather than relying on one impressive percentage. Good coaching begins with an individual's actual performance, not assumptions about the group they belong to.
Why the Bench Press Favored Women in Percentage Terms
The bench press result looks decisive at first glance: a 32.8 percent improvement versus 19.9 percent is a substantial gap. But imagine one lifter starts with a 100-pound bench and reaches 130 pounds. That is a 30 percent increase. Another starts at 200 pounds and reaches 230 pounds. Both added exactly 30 pounds, yet the second lifter records only a 15 percent improvement. The hypothetical example illustrates why a bigger percentage does not automatically mean more absolute strength was gained. Neither metric is wrong; they answer different questions.
In the experiment, the women's percentage bench-press improvement was significantly greater, but the difference was not significant when the researchers compared the actual weight added. Starting strength helps explain the contrast. An athlete with a lower baseline has a smaller denominator in the percentage calculation. This is especially relevant to upper-body movements, where average starting strength often differs across groups. A percentage change can be useful for describing improvement relative to where somebody began, but it should not be mistaken for an equal playing field in kilograms or pounds.
Bench-press performance is also more than chest size. Technique, confidence under a loaded bar, the ability to keep the upper back stable, consistent bar path and improved coordination can all affect a one-rep-max test. Training a lift twice weekly gives participants repeated opportunities to refine those skills. Early improvements can therefore reflect both muscular adaptations and better expression of existing capacity. A study of twelve weeks cannot tell us that the same percentage gap would continue indefinitely as everyone becomes more technically proficient.
For your own bench press, record the load and the number of controlled repetitions at a comparable effort. If you progress from 95 pounds for eight reps to 105 pounds for eight with the same range of motion and no extra help from a spotter, that is meaningful progress regardless of how somebody else's chart looks. Use safety pins or a competent spotter for maximal attempts, and avoid testing a true maximum every week. Build a repeatable practice first; let occasional strength tests confirm what your training log already suggests. The percentage is a useful footnote, not the entire story.
The Hex-Bar Deadlift Flipped the Result When Pounds Counted
The deadlift results tell almost the reverse story. Men added an average of 29.4 kilograms to their hex-bar deadlift, while women added 14.4 kilograms. In pounds, that is roughly 64.8 versus 31.7. Judged solely by absolute load, the male group made a larger gain. Yet when the researchers expressed the same improvement as a percentage of starting strength, the between-group difference was no longer statistically significant. The exercise did not change halfway through the analysis. The unit used to describe improvement changed.
That is why strength comparisons need context. An absolute increase is highly relevant when the goal is moving a heavier object: if a lifter adds 65 pounds to a deadlift, the bar is 65 pounds heavier. A relative increase is useful when discussing how far somebody has moved from their own starting ability. Neither number should be used alone to rank the quality of a training program. Athletes of different sizes, training ages and starting capacities can make impressive progress that appears modest under one measure and dramatic under another.
The hex bar also has specific technical demands. Its handles place the load around the lifter rather than in front of the shins, and many models allow different grip heights. Those details can alter joint angles, range of motion and how much weight an athlete can move. Comparing a high-handle hex-bar lift to a conventional straight-bar deadlift would introduce another variable. In a fair progress check, use the same bar, handle height, stance, footwear and approximate effort. Consistency of the test matters before you start debating who improved faster.
Practically, train a hinge pattern you can load safely and progress. Brace before each repetition, keep the load close to your center of mass, push through the floor and finish tall without leaning back. Work with a manageable weight for sets of five to eight before chasing maximal singles. A lifter who adds twenty pounds while keeping form and recovery intact has achieved something useful. Whether that represents a ten or twenty percent gain depends on the starting point. The deadlift finding is a reminder to celebrate both kinds of improvement without confusing them.
Muscle Growth Was Much More Similar Than the Strength Headlines
Here is the part most relevant to people who train primarily for physique: the men and women showed broadly similar increases in the two measured muscle regions. Biceps thickness rose by approximately 14 percent and vastus lateralis thickness by approximately 10 percent, without a statistically significant between-group difference. That is not the same as proving that every participant gained identical muscle mass. Ultrasound thickness is a local measure, and the study was relatively small. Still, it directly challenges the idea that the group with the bigger strength percentage must have built more muscle.
Muscle size and one-rep-max strength overlap, but they are not interchangeable. Hypertrophy reflects changes in muscular tissue, while a maximal lift also depends on technique, coordination, leverage, motivation and familiarity with the test. You can improve your squat through better bracing before a tape measure changes, and you can grow your biceps without producing a spectacular bench-press personal record. For bodybuilders, the better question is whether a program delivers hard, repeatable work for the target muscles over enough time to produce a trend.
Broader evidence points in a similar direction. Research pooling multiple resistance-training studies has generally found comparable relative muscle growth between men and women who follow the same intervention, even when some absolute changes differ. This does not erase biological differences or individual variation. It means there is little reason to assume a woman must use an entirely different category of exercises or a man needs a completely different hypertrophy mechanism. Both benefit from appropriate effort, sufficient training volume, progressive overload and recovery.
If you want bigger quads, track your squat or leg-press performance alongside consistent photographs, measurements and how your clothes fit. If you want stronger arms, pair curls with rows and presses while keeping technique repeatable. Avoid overinterpreting day-to-day bodyweight fluctuations or one unusually good session. Muscle growth is slower to assess than a one-rep-max test, and measurements have noise. The 12-week data are encouraging precisely because they separate two outcomes that gym conversations routinely mash together: how much you can lift and how much muscle you have built.
A Two-Day Strength Plan That Works Without Gender-Specific Rules
The most useful application is a straightforward program that adjusts the load to the individual, not to a stereotype. Two full-body sessions each week can cover the major movement patterns and provide enough exposure to practice the lifts. Start with weights that allow controlled repetitions while leaving about one to three reps in reserve. A beginner might need fewer sets and more technique practice; an experienced lifter may need more hard work or a different progression rate. The structure can be shared while the loading remains personal.
On Day A, begin with a squat or leg press for three sets of six to ten repetitions. Follow with a bench press for three sets of six to ten, a chest-supported row for three sets of eight to twelve and a leg curl for two sets of ten to fifteen. Finish with two sets of biceps curls and a brief trunk exercise if time allows. Warm up gradually before the first demanding set. Rest around two to three minutes after challenging compound lifts, and a little less on smaller accessories when performance permits. Keep the same exercises long enough to see a real trend.
On Day B, start with a hex-bar deadlift or Romanian deadlift for three sets of five to eight. Add a split squat for two or three sets per leg, an overhead or incline press for three sets of six to ten, and a pulldown for three sets of eight to twelve. Finish with leg extensions and triceps work for two sets each. If an exercise causes persistent joint discomfort, substitute a movement that trains the same pattern without provoking symptoms. There is no prize for keeping an exercise that you cannot execute comfortably.
Use double progression rather than forcing heavier weights every session. For example, keep a weight until all three sets reach the top of an eight-to-twelve-rep range with good technique and the intended effort. Then add the smallest practical increment and work back up. For upper-body lifts, that may be 2.5 to 5 pounds; for lower-body lifts, 5 to 10 pounds may be appropriate, but the right jump depends on equipment and ability. If reps drop for several workouts while fatigue rises, reduce the workload temporarily before assuming you have hit a permanent plateau.
Record loads, repetitions and the approximate effort of each set. Do not compare one lifter's 135-pound squat to another's 225-pound squat as though the number alone reveals training quality. Both can be working at a similarly challenging relative intensity. Recovery, food intake, sleep, exercise history and consistency will influence the outcome more than a gender label printed on the program. The shared principles are progressive practice, enough hard sets and patience. Individualization belongs in the details.
How to Read Your Progress Without Letting the Numbers Mislead You
A training log should tell a coherent story, not merely produce the largest possible percentage. Start with three separate questions. Did the actual load or number of repetitions increase? How large was that change relative to the starting point? And did the target muscles appear to grow over a meaningful period? A lifter can answer yes to one and not the others. The categories are related, but none substitutes perfectly for another. Treating them separately keeps a normal training plateau from looking like failure and a temporary test-day spike from looking like guaranteed muscle growth.
Use consistent conditions when comparing lifts. A bench press with a controlled pause should not be treated as equivalent to a bouncing touch-and-go attempt if the goal is a clean strength trend. A deadlift using raised handles is not the same test as one pulled from the floor. For hypertrophy, take progress photos with similar lighting and body position every four to six weeks rather than judging the mirror immediately after a pump. Track bodyweight trends over multiple mornings if changes in size matter to your goal. Consistency makes imperfect measurements much more informative.
Be cautious about interpreting significance, too. When a study finds no statistically significant difference between groups, that does not prove they are perfectly identical. It means the available data did not establish a difference under the analysis used. Likewise, a significant percentage difference does not necessarily tell you that one approach is superior for every person. Small samples, baseline strength, measurement methods and the length of training all matter. The responsible reading is that the same program can produce substantial improvement in both groups while the apparent winner changes with the metric.
Finally, choose goals that are yours. A recreational lifter might care about pressing a weight they could not move last month, filling out a shirt or keeping training enjoyable. A powerlifter needs the actual weight on the bar in a competition-standard lift. A bodybuilder may prioritize regional muscle growth even if their one-rep-max rises slowly. None of those goals is less legitimate. The new results make a simple point worth remembering: a strength percentage is a description, not a destiny. Train consistently, measure honestly and let your own trajectory guide the next block.
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