man bicep curling a straight bar from behind (huge back muscles)

7 Weirdly Scientific Things the Gym Bros Were Right About All Along

When bro science meets actual science.

10-Second Takeaway

Pushing yourself, psyching yourself up, and not sweating the small stuff can take you far in the gym. Believe it or not, it’s possible to work out like a bro and not be a jerk.

Bro science doesn’t have a hard definition—it’s a you-know-it-when-you-hear-it kind of thing—but, to my knowledge, it was best summarized by BroScienceLife’s Dom Mazzetti in a brief, largely unfollowable video titled What Is Bro Science?: “Every jacked dude in the gym is a goldmine of unfounded tips on how to get huge,” he says. “Bro science is great because you don’t have to waste time explaining real science. I believe it works, and that guy just told me, and he’s [expletive] huge.” 

That last line is important because it tells us the roots of bro science are anecdotal, which any good trainer would say should not be dismissed. And though bro scientists—is there a degree program?—get a lot of flak for their misses, they haven’t been proven wrong about everything. On the contrary, they’re often right about the most essential aspects of resistance training. These are the ideas the bros were (mostly) right about.

1. Psyching yourself up actually boosts performance

Balk as you may at the gymgoer who screams before (and probably after) a heavy deadlift, the reality is they’re just following the latest science. 

In a review of 27 studies on psyching-up as a tool to bring about maximal force production—how much power you can generate—65 percent concluded that “psyching up” facilitated maximal force production (1).

In the context of the studies, psyching up was defined as “free-choice psyching-up, motivational self-talk, PETTLEP imagery, and prescribed preparatory arousal”—in other words, cheering yourself on.

Next time you’re going for a PR, try freeing yourself from the shackles of our collective social contract and, as respectfully as possible, act an absolute fool—it’s science.

one man does pushups and one-armed rows and the other watches him intently
There’s quite a lot of genuine, peer-reviewed science supporting the value of working out with a buddy. (Photo: Getty Images // Design: Hone Health)

2. Working out boosts testosterone

Does working out boost your testosterone? The short and long answers are both yes, but with some caveats and a touch of nuance. 

Most studies find men who work out have significantly higher levels of testosterone than men who don’t (2). There is a direct link between carrying too much weight on your body and low testosterone (3). One study found that increased exercise boosted testosterone levels, suggesting that simply working out may augment testosterone levels (4).

It’s probably easiest to view strength training and testosterone as a feedback loop. Strength training builds muscle, more muscle means more muscle fibers recruited for workouts, and more muscle fibers worked means a bigger testosterone boost. And finally, since testosterone is an anabolic hormone (a hormone that builds muscle), more of it helps you both build and retain said muscle, which puts you back at the beginning of this very handy circle.

3. Turning up the intensity

There’s a nuanced, in-depth discussion to be had about whether high intensity (load) with low volume (sets and reps) produces better results than moderate intensity with high volume. There is plenty of evidence for either—but the reality for many folks not getting the gains they so desire is often simpler: they’re not pushing themselves enough. 

Other than proper nutrition and sleep, to build muscle and strength in the long term we need progressive overload. For progressive overload, we need to continually ratchet up the intensity of our workouts—whether that be through more sets, more reps, more weight, or any number of other means. 

The problem is, research has often found that lifters—both trained and untrained—really suck at identifying their own intensity, at least when it’s measured by reps in the tank. A 2020 study on the subject found that “perceptions of effort during resistance training task performance may not be congruent with the actual effort required” for building strength or muscle (5). Another study from 2021 found participants “were imperfect in their ability to predict proximity to task failure independent of their training background.” AKA it didn’t matter how experienced they were, they still kind of sucked at estimating how many more reps they could push (6). One study went as far as stating that trained people working toward self-determined maximum repetitions were “not efficacious” (7).

Well-trained and untrained people are not consistently able to estimate their intensity levels, according to the majority of studies and reviews on the subject. The one big and useful “but!” is this: the closer to failure trainees get, the more accurate their assessments of fatigue become (6, 8, 9). This is not a pass to ego lift, or lift to absolute failure on every set, but it is helpful to know you have a better chance of accurately predicting your intensity the closer you get to a true failure point. 

4. Working out with a partner increases gains 

It’s common to train with a gym partner as an accountability tool, or perhaps someone to give you a hard wake-up call when you’re not pushing yourself, but it’s not just bro science. 

A 2023 study compared the pre- and post-program body compositions of 36 young, trained individuals—half of whom worked out supervised, half of whom worked out alone. Both groups were given the same workout program, but the group that worked out with a partner supervisor saw better or equal results across all measurements but one (10). 

This isn’t to say you must work out with a partner, of course—working out might be a scheduled social escape for you, or perhaps none of your social connections work out as hard as you do—but it does mean you might be leaving some gains on the table if you fly solo.

Science of Lifting

5. Perfect form isn’t always a must

Ask anyone who knows anything about resistance training and they will (rightly) tell you technique is critical in the gym. But what the bros have known—and said, loudly at times—for decades is that ultra-strict technique matters less than simply doing the work. They’re probably right. 

In a narrative review of more than 40 studies on muscle hypertrophy, researchers in a 2023 study (11) distilled what the current evidence suggests is optimal to build muscle: “Based on the current available evidence, we recommend that exercise technique in [resistance training] programs designed to maximize muscle hypertrophy should employ a [range of motion] that allows a muscle to be fully stretched while utilizing an eccentric and concentric phase duration that spans an overall repetition duration of 2-8 seconds.” 

Translated into regular English, what they found is that folks should lift in a large range of motion that stretches that targeted muscle(s) and that they shouldn’t rush through reps. That is shockingly broad, which the researchers acknowledge in the study. That rep duration range recommendation allows for exploding up-and-down reps and slow grinders. 

So get your form down, but don’t allow overanalyzing your technique to step in the way of consistently getting in the gym and training at proper intensity levels. 

6. Not sweating rest times 

There’s a lot of consternation around how long one should rest between sets for muscle growth. Why? We’re not really sure, and neither is the science. 

In a 2024 literature review of the science of rest times for hypertrophy, researchers found a small benefit to rest times greater than a minute, with “unclear” results beyond 90 seconds (12). This supports the long-held belief of the gym-educated that rest periods are best practiced on how you feel, so long as you’re giving yourself at least a brief recovery period. 

Finish up a heavy squat set with another one coming up? Give yourself a few minutes—let your heart rate come to a normal level, allow your quads a moment to stop shaking, and get under the bar again when you’re mentally and physically prepared to do it again. Unless you’re working out with very little time on your hands, resting an extra minute is probably not going to hurt your gains—but starting a hard set before you’re ready might. 
All this said, rest times, like all variables you can tinker with at the gym, should be tailored to your goals. Heavy strength training usually comes with a lengthier rest period recommendation—2 to 5 minutes—while muscular endurance training rest period recommendations are typically 30 seconds or less (13).

Brain Gains

7. Heeding the mind-muscle connection 

Out of context, the term “mind-muscle connection” sounds like total nonsense. Coined decades ago—likely before or during bodybuilding’s “Golden Age” (Arnold Schwarzenegger’s time)—mind-muscle connection is purportedly a powerful tool for muscle growth. It can be described as actively feeling the target muscle group spool out and contract with every rep—in other words, mentally focusing on the muscles moving the weight, every rep, every set. 

If you think that sounds like bro science, you might be a passive lifter. In a column from the world’s preeminent muscle hypertrophy master, Dr. Brad Schoenfeld, C.S.C.S., C.S.P.S., N.S.C.A.-C.P.T., outlines the value of the mind-muscle connection—called “internal attentional focus” in the research (14).

“…when attempting to maximize muscle activation, an internal focus of attention would seem to be a better choice. Bodybuilders, physique athletes, and others seeking maximal hypertrophy will conceivably benefit by focusing on the target muscle during an exercise rather than on the outcome or environment. It is likely that the molecular signaling for all 3 primary mechanisms of muscular hypertrophy, namely mechanical tension, metabolic stress, and muscle damage, are increased when the exerciser focuses their attention internally, which could ultimately result in greater muscular development for a given exercise and load.”

The takeaway? Don’t go on autopilot during sets—feel the muscles you’re trying to work move through each rep. Lock in. It will be worth it. 

But, and there’s always a but, if your goal is purely pushing bigger numbers on your lifts, you might be better off shifting your focus more toward form, safety, and exerting the most force you possibly can. Studies show a razor-sharp focus on, say, your chest while lifting heavier weights might actually reduce your potential one-rep max (15). 

  1. Cusimano, Kurtis et al (2024) The Effects of Psyching-Up on Maximal Force Production: A Systematic Review
  2. Yeap, Bu B. et al (2020) Sociodemographic, lifestyle and medical influences on serum testosterone and sex hormone–binding globulin in men from UK Biobank
  3. Hisasue S. (2015) Contemporary perspective and management of testosterone deficiency: Modifiable factors and variable management
  4. Kumagai, Hiroshi et al (2015) Increased physical activity has a greater effect than reduced energy intake on lifestyle modification-induced increases in testosterone
  5. Armes, Cedrik et al (2020) “Just One More Rep!” – Ability to Predict Proximity to Task Failure in Resistance Trained Persons
  6. Halperin, Israel et al (2022) Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis
  7. Gieβsing, Jùrgen et al (2016) The effects of low-volume resistance training with and without advanced techniques in trained subjects
  8. Halperin, Israel et al (2021) Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis
  9. Hackett, Daniel A. et al (2019) Associations between Perceptual Fatigue and Accuracy of Estimated Repetitions to Failure during Resistance Exercises
  10. Coleman, Max et al (2023) Supervision during resistance training positively influences muscular adaptations in resistance-trained individuals
  11. Korakakis, Patroklos Androulakis et al (2024) Optimizing Resistance Training Technique to Maximize Muscle Hypertrophy: A Narrative Review
  12. Singer, Alex et al (2024) Give it a Rest
  13. Willardson, Jeffrey M. (2008) A Brief Review: How Much Rest between Sets?
  14. Schoenfeld, Brad () Attentional Focus for Maximizing Muscle Development: The Mind-Muscle Connection
  15. Snyder, Benjamin J. (2012) Effect of verbal instruction on muscle activity during the bench press exercise