New Study on 200+ People Reveals Half Your Gym Time Might Be Wasted (Here’s the Exact Number of Workouts You Actually Need)

Popular fitness YouTuber Jeremy Ethier just wrapped up one of the largest training experiments ever conducted outside a university lab, and what he discovered challenges a belief many lifters hold sacred: more time in the gym equals more muscle.

The experiment tracked over 200 real people for 10 weeks, comparing those grinding through six workouts weekly against others training just three days.

The results were shocking—and might completely change how you approach your training.

Spoiler: half your gym time might be doing absolutely nothing for your gains.

The Experiment That Changed Everything

Ethier recruited 200 lifters and randomly assigned them to one of two groups. The first group followed a six-day push-pull-leg split with approximately 20 sets per muscle per week—essentially the gold standard many serious lifters follow.

The second group performed the same push-pull-leg routine but only three times weekly, cutting both workouts and total sets in half.

To control for nutrition, every participant followed a small calorie surplus with minimum daily protein targets, all tracked through the Built with Science app. Anyone who wasn’t consistent got kicked out. Both groups were carefully balanced for gender and experience level, with equal numbers of beginners and intermediate lifters in each.

Dr. Eric Trexler, a statistician and muscle growth researcher, helped design the study and independently analyzed all data.

With this kind of design, what we do is we sacrifice the high-tech body comp measurements so that we can expand out and get a more, you know, a larger, more representative sample.

Early Signs Something Was Different

Just three weeks in, a clear pattern emerged. The six-day group was struggling.

This week, I missed a few morning workouts. Had to do them at night after leaving the office. I started to dislike the 6 day split a bit.

Meanwhile, the three-day group reported feeling energized and motivated.

Going into the gym only 3 days a week, I am giving 110% rather than cutting corners here and there.

Participants rated workout difficulty weekly. During the first four weeks, the three-day group consistently found their sessions easier and more sustainable. The six-day group? Not so much.

It’s a lot. It’s definitely tough to hit six days of the week. My muscles are still sore when I work out. Probably tougher than I expected.

One participant even reported feeling nauseated and vomiting after leg exercises.

Confidence vs. Reality

Despite the fatigue, the six-day group remained confident their program was superior. After all, over a decade of research suggests more volume equals more growth.

But as weeks progressed, something interesting happened. The three-day group kept reporting feeling stronger and lifting heavier week after week.

I think maybe I did push myself harder because I only had 3 days. I’m like, we got to make these count. We got to go hard. We only have 3 days.

The six-day group sounded like they were just trying to survive.

I don’t know that I would recommend anybody to follow this kind of program. Maybe if I were half my age, it wouldn’t be such a big deal.

The Results: A Statistical Tie

After 10 weeks, Dr. Trexler crunched the numbers. Combined muscle growth in the six-day program averaged 0.83 inches. The three-day group? 0.75 inches.

That looks like a meaningful difference but it’s important to understand that that was not nearly a significant difference between the two and any statistician would look at these data and say those two groups essentially grew the same amount.

Translation: The three-day group did half the work and got virtually identical results.

This contradicts what research typically shows. When studies compare 10 sets per muscle weekly to 20 sets, the higher volume group usually sees about 60% more gains. By that calculation, the six-day group should have seen 1.2 inches of combined growth, not just 0.83.

So what went wrong?

Why High Volume Failed: The Effort Problem

Dr. Eric Helms, a muscle researcher and natural pro bodybuilder, offered a compelling explanation: your muscles don’t respond to how many sets are written in your program. They respond to the actual stimulus those sets create.

There’s absolutely scenarios in my coaching experience where people have done something like going from 20 plus sets to say in the teens and started to grow better or more or break a plateau and it’s because the actual dose was higher when they dropped the volume. It’s just that they did everything else better and they didn’t realize how much they were sandbagging.

A 2014 study illustrated this perfectly. Researchers had participants perform 12 sets of maximal bicep contractions. Half knew they’d do 12 sets total. The other half were told they’d only do six—but actually did 12.

Despite instructions to push maximally on every set, the group expecting 12 sets paced themselves and produced consistently less power than those who thought they only had six sets to complete.

The Subconscious Sabotage

This psychological phenomenon likely plagued Ethier’s six-day group. Knowing they had twice the training volume probably caused them to:

• Subconsciously hold back on effort
• Let form slip as fatigue accumulated
• Stop sets earlier than they should
• Mentally coast through workouts just to survive

There’s an accumulation of fatigue. I need to pace myself more. It’s just it’s just a lot of volume to do six days a week.

Why Studies Still Show More Volume Works

If higher volume can backfire in the real world, why do research studies consistently show it builds more muscle?

Simple: supervision.

Research studies isolate volume as a variable while controlling everything else. Participants are watched, coached, and pushed to maintain effort and form across all sets—something that doesn’t happen when you’re training alone.

A brand new study published just days before Ethier’s video demonstrated this perfectly. One group trained under supervision while another did the identical program unsupervised. After eight weeks, the supervised group gained more than a pound of additional fat-free mass and grew more in virtually every muscle measured.

In the real world, unless someone is watching every rep, you’re left to manage intensity yourself. And if you don’t, extra gym time goes to waste.

Three Tests to See If You’re Wasting Time

Here’s how to determine if your training effort is actually translating to results:

Test #1: Rep Speed

Your last few reps should move noticeably slower than your first reps. If they don’t, you’re stopping too soon.

Test #2: Rep Drop-Off

Across three sets with the same weight, you should see performance decline. Maybe 12 reps in set one becomes 11 in set two, then 9 or 10 in set three.

If your reps stay flat or somehow increase on your final set, you didn’t push hard enough earlier.

Test #3: Progressive Overload

This is the most important test. Look back at the last 2-3 months. Are you consistently adding reps or weight to your main lifts?

If yes, your program is working. If you’re training five or six days weekly and your lifts haven’t budged in months, you might benefit from cutting back.

It might not be a terrible idea to do a little experiment with yourself. You know, try to cut down on your volume for a training block or two. Really push your intensity. Be very intentional about bringing effort into your sessions.

Dr. Helms suggests trying just two hard, high-quality sets per exercise instead of three or four. If you find yourself more focused and pushing harder without performance dropping, you were probably wasting time on low-effort sets.

What About Advanced Lifters Who Train Hard?

Let’s say you’re experienced, know how to push close to failure, maintain excellent form, and give every set maximum effort regardless of total volume. Surely doing significantly more volume would build more muscle, right?

Not necessarily.

Shortly after Ethier’s experiment concluded, researchers published a similar study comparing roughly 36 weekly sets for arms and thighs against just nine sets—four times the volume. Unlike Ethier’s experiment, every workout was supervised to ensure the high-volume group maintained effort.

Result? The higher volume group did grow slightly more, but the difference was minimal and not statistically meaningful.

Every single set you start adding and especially once you get into the teens and 20s is such a marginal return on investment.

That said, for elite natural bodybuilders like Dr. Helms competing at the highest level, even marginal gains matter. The question becomes whether you’re willing to invest significantly more time for incrementally better results.

The Surprise Winner: Three-Day Full Body

Ethier’s experiment included a third group that technically achieved the best results: a three-day full-body program using supersets.

This group took all the volume from the six-day split and compressed it into three full-body sessions. Average growth was 0.87 inches—slightly greater than the six-day program, though not statistically significant.

The likely reason? Frequency.

By spreading the same total volume across more frequent sessions per muscle group, participants avoided the performance drop-off that occurs when doing set after set after set of the same movement.

Dr. Helms actually structures his own training similarly—but takes it further with six workouts weekly, each split into morning and evening sessions. This maximizes total volume while keeping individual workout quality sky-high.

Practical Recommendations: What Should You Do?

Your ideal training frequency and volume depend on your goals and lifestyle.

For Maximum Muscle Growth (Advanced Lifters)

If you’re willing to invest significant time and can maintain high effort across all sessions:

• 15-20+ sets per muscle per week
• Higher training frequency (hitting each muscle 2-3+ times weekly)
• Consider splitting sessions (morning/evening) to maintain quality
• Full-body or upper/lower splits work well

For Solid Gains Without Massive Time Investment

If you want excellent results while maintaining life balance:

• 10-15 sets per muscle per week
• 3-4 training days weekly
• Push-pull-legs or full-body splits
• Focus intensely on effort and progressive overload

Ethier himself trains hard four to five times weekly, getting about 60-70% of maximum potential gains—a trade-off that makes sense for his lifestyle.

If You’re Currently Training High Volume Without Results

Cut volume by 30-50% and focus obsessively on:

• Pushing closer to true muscular failure
• Maintaining perfect form on every rep
• Adding weight or reps weekly
• Recovery and nutrition quality

You might be shocked to discover you grow better on less volume when effort dramatically increases.

The Bottom Line

More gym time doesn’t automatically equal more muscle. In fact, for most people training in the real world without supervision, excessive volume becomes counterproductive because effort inevitably drops.

The sweet spot for most lifters appears to be 3-4 hard training days weekly with 10-15 quality sets per muscle. This allows you to bring genuine intensity to every set without burning out or subconsciously sandbagging.

Advanced lifters chasing every last percentage point of growth can benefit from higher volumes—but only if they can genuinely maintain effort and recovery. For everyone else, training smarter beats training more.

As one of Ethier’s participants discovered the hard way, sometimes less really is more.

I just spent 10 to 11 hours of this week training and I could have gotten almost the same outcome doing a third of that. Like it it’s it’s it’s stupid, right?

The question isn’t how much you can train. It’s how much you can train while maintaining the intensity that actually builds muscle.