“Train to failure!” It’s a mantra you’ve probably heard in the gym, many programs call for it, and many people say they do. But do they actually train to failure?
A brand new study—so hot off the presses that it hasn’t even been peer-reviewed yet—called The Effects of Supervision Upon Effort During Resistance Training looks at how much having someone supervise your training impacts your effort, time under load (TUL), and perceived effort.1
Turns out, having a watchful eye (and maybe someone to yell at you to do one more rep, one more rep!) can push you that much closer to failure—and that’s where you want to be for real muscle growth.
The study compared supervised and unsupervised strength training sessions to determine how much harder people train when someone holds them accountable. The results? Supervision significantly improved TUL and effort, suggesting that many of us might be slacking more than we think when left to our own devices.
Why Training to Failure Matters for Muscle Growth
Muscle growth happens when you push your muscles beyond their comfort zone.
It doesn’t happen right then and there in the gym, but the closer you get to actual momentary failure (where you physically cannot lift the weight again), the more muscle fibers you recruit and fatigue, and the stronger signals you turn on that tell your body to kickstart muscle protein synthesis (the process where amino acids get incorporated into new muscle protein).
This, in turn, leads to adaptation in the form of muscle hypertrophy (growth).
However, many people stop too soon—often well before failure—either because of discomfort, mental fatigue, or simply because no one pushes them to keep going.
This new study suggests that supervision might be an underrated factor in making people push themselves to the limits required for maximum muscle growth.
How the Study Was Conducted
The study was conducted at private strength clinics in Australia, where members trained either:
- Unsupervised – Training on their own, following prescribed workouts.
- Supervised – Training under the guidance of a qualified exercise scientist.
The researchers analyzed both retrospective data from 1,000 members in each category and conducted an experimental study with 45 participants who trained both supervised and unsupervised in a randomized order.
They used the following machines:
- Hip Extension
- Torso Flexion
- Hip Abduction
- Leg Extension
- Leg Press
- Seated Leg Curl
- Pulldown
- Seated Row
- PecFly
- Chest Press
- Seated Dip
- Abdominal Flexion
- Supported Supinated Grip Pull-Up
Not all participants used every machine, but they had at least some of these machines included in their personalized workouts.
The participants were instructed to train to momentary failure, using their usual loads, to see if supervision made a difference.
While all participants followed this protocol, those in the supervised condition had their progression managed by an exercise scientist, whereas those in the unsupervised condition self-selected their progressions.
The researchers then measured the performance of the participants using:
- Time Under Load (TUL) – How long the trained muscles were under tension.
- Rating of Perceived Effort (RPE) – How hard the participants felt they were training.
- Rating of Perceived Discomfort (RPD) – How much discomfort they experienced.
The study’s design ensured that participants performed their sessions under similar conditions, with the only variable being the presence or absence of supervision.
Supervision Leads to Higher Effort and More Time Under Load
The study found that supervision had a notable impact on training effort and performance.
When participants trained under supervision, their Time Under Load increased, as did their perceived effort and discomfort, meaning they pushed themselves closer to failure when an exercise scientist guided (yelled at) them.
Time Under Load
- Unsupervised TUL: 125.12 sec
- Supervised TUL: 147.35 sec
Supervised trainees trained 22.1 seconds longer on average.
Perceived Effort
- Unsupervised RPE (effort level): 81%
- Supervised RPE: 87%
Supervised trainees pushed themselves 6% harder.
Perceived Discomfort
- Unsupervised RPD (discomfort level): 6.3
- Supervised RPD: 7.5
Higher discomfort suggests that the participants pushed themselves more when someone was overseeing their training, and many likely stop too soon when training alone.
Unsupervised Trainees Were More Likely to Stop Prematurely
- Core trainees stopped at 120 seconds in 15% of sessions.
- Supervised trainees stopped at 120 seconds only 1% of the time.
This suggests that unsupervised trainees often stick to arbitrary stopping points rather than true muscle failure.
What Does This Means for Your Training?
Many lifters underestimate how hard they are capable of training. When the going gets tough, you might terminate a set way before you’ve reached actual muscular failure. You might even think you have reached failure even though you could do one, two, or even more reps, more if someone held you at gunpoint.
If you don’t have a trainer, try finding a training buddy who can encourage you to squeeze out those extra reps.
When training alone, make a conscious effort to push past mental roadblocks.
If you always stop at 10 reps because that’s what your program says, you might be missing out on untapped potential. Slap on more weight on the bar or do more reps.
Higher discomfort levels in the study correlated with higher effort—embrace the pain. I’m not talking about injury pain, of course, but the burn of getting close to failure. Those who have trained to failure in compound exercises like the squat know that feeling when your entire body wants to give up in a cloud of pain. Whatever it takes, right?
In short, if you’re regularly stopping as soon as things get tough, you might be leaving gains on the table. Even if you think you are training to failure, ask yourself: am I really?
Lastly, consider hiring a coach and pay them to scream at you and push yourself as far as possible. Even if it’s just a single supervised session, it can set a benchmark for how hard you should be training.
Final Rep
While you can make terrific gains solo, training with supervision, like a partner or an accountability system, can help push you to your true limits—where maximum muscle growth happens.
This new study confirms what many gym rats already know: having someone watching you makes you work harder.
So next time you’re about to rack the weights thinking you’re “done,” ask yourself: “Would I have stopped if someone was watching?” If the answer is no, you probably have a little more left in the tank.
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