This Shouldn't Work, But It Blows Up Your Muscles (In 30 Days)

What if you could force months of muscle growth into just 30 days? I have a theory you can, using a method everyone says shouldn't work. Training a muscle every single day. And I'm testing it on these 3 people to see if it actually works and how different muscles respond. Chest for Brandon, arms for Yelinda, and legs for Max. But to compare just how effective it is, each person will work out their right side every day and the other side just twice a week. The fuck side grew almost 20%.

What?

It'll be 5 sets, 8 to 12, and it's gonna be hard sets.

Um, what happens when you're really sore?

That's part of the experiment.

We'll try to do 5 sets of 9 to 12 every day with this right leg. You're the horse. Build some horse legs.

Some of you might remember Max from our past experiment where he ate only chicken, potatoes, and broccoli for 30 days. He's the only person I could find crazy enough to work out one leg every day.

Got a text from Jeremy and I just came straight here and here we are again, another 30-day challenge.

On day 1, all 3 participants got MRI scans of each side to measure their baseline. We'll scan them again on day 30. And we already have mixed predictions on which side will grow more.

Probably the one that's trained every day, if I had to guess.

Really?

No rest days needed, I'm still young.

I think rest will make you recover.

Rest will make you recover and grow more. That's locked in?

It's locked in.

It's locked in. Okay.

$1,000?

$1,000?

Now, Max and Yolinda's guesses line up with what gym bros and researchers have preached for years. If you don't allow enough time for the recovery phase, you're not going to get the growth phase at the end. And these guys aren't wrong. When you train hard, your muscle fibers experience extremely high tension, which delivers a powerful signal for it to grow, but it also makes it temporarily weaker. So within hours, immune cells move in to help clean up damaged tissue and coordinate repair, and muscle protein synthesis, which is the process that actually grows your muscle, begins and often continues for 24 to 48 hours after training. If you train again before this healing process is complete, you interrupt it, which is why most programs recommend at least 1 to 2 days of rest between training the same muscle. But what happens if you don't wait? Can your body adapt to no longer need rest, or will all that unrepaired damage lead to something worse?

So it's day 4 of this one leg challenge. I've been training my right leg every day and I don't know, I'm feeling really sore now.

Definitely feeling the fatigue in my everyday arm.

Other days are flies because the press puts too much stress on my shoulder and tricep.

So far things aren't looking too promising. On top of that, fitting in a workout every single day has been a challenge.

It is currently 11 PM. Instead of going to sleep, I'm going to go work out.

I just got home from a hockey game. And I realized that I didn't do my workout today. I was sitting on my adjustable bench for 5 to 10 minutes just debating, just push through one more chest workout.

Meanwhile, Max is actually loving the daily leg training until he notices something serious.

When I do squat, I feel like it's a little bit off balance now.

But for now, everyone's biggest concern is the soreness. If a muscle is still sore, it's damaged. And if it's still damaged, training it again is, well, just dumb, right?

There's a reason it's called delayed onset of of soreness. There's typically a 1 to 2 day delay for most people to experience the peak of soreness.

That's Dr. Eric Helms, a muscle growth researcher who was on a mission to crack the top 5 on the world's most competitive natural bodybuilding stage. And what he told me about muscle soreness went against everything I thought I knew.

If you train today really, really hard to the point that it'll generate DOMS, your force production decline will be lowest of course the same day within that same session, and then it gets progressively better and recovers. And often the time point at which delayed onset muscle soreness is the highest, is right around the same time when force production has returned to baseline or close to it.

Basically, your muscles can be ready to train again well before the soreness actually goes away. So even though everyone's muscles felt destroyed, the real test was whether they could still perform.

So I've been doing these Bulgarian split squats every day for my right leg, and it's not really affecting my strength, so it's good. The soreness is just there, but strength is still maintaining here. When I do play pickleball, I almost slipped the other day and I was able to catch myself with my right leg.

And then just 8 days into the experiment, something interesting happened.

Honestly, the soreness just kind of faded away now. Just keep going with this one leg, feels fine.

Now according to Eric, there's actually a name for this.

But so is what's called the repeated bout effect, which just means that when you repetitively do the same thing that challenges the muscle and produces muscle damage, it gets drastically reduced with time and with exposure.

The daily training was forcing their muscles to adapt and recover much faster, to the point where they were no longer getting sore at all. But so far, it was very difficult to tell what side was winning.

Haven't noticed too much on the muscle development here. Both legs, they look quite, quite similar in size here. So no change.

My everyday arm feels stronger than the other one. But appearance-wise, I think it might still be a little too early to tell.

Now, you can't expect to see huge visual muscle growth in just a few weeks, which is exactly why we're using MRI to detect changes the eye and most basic lab equipment just can't pick up. But there was one sign daily training might be working.

I'm very happy to report that I have been consistently curling 15-pound dumbbells with some plates here and there for my bicep curls. I have never been able to curl anything over 12 pounds before, so very happy to see the improvement.

In fact, based on the workout logs in their Built With Science app, even though each person had bad days where the Everyday side got weaker, week by week its strength kept climbing and actually started pulling ahead of their normally trained side. But just as the Everyday side started looking like the winner, during a set of leg extensions, Max felt a sharp pain in his knee. And that's when I started getting worried, because even if your muscles can adapt to daily training, the same isn't true for your joints and tendons. In fact, in a study published just last year, trained lifters benched every single day for 34 days straight. Now, by the end of it, every single one of them gained insane amounts of strength, shattering their day one personal records, but over half of them ended up getting hurt. So before letting the experiment continue, I wanted to ask Eric for his honest prediction of whether daily training could work or not. Otherwise, I might just be risking getting people injured for nothing.

I think whichever side was doing more total volume and that was doing more of that total volume closer to failure would probably have slightly more growth.

See, the Everyday side isn't just training more often, it's doing way more total work. About 35 hard sets per week compared to 10. And one of the most consistent findings in exercise science is the more hard sets you do for a muscle, the more it tends to grow. But here is the problem. Most people just can't cram 30+ hard sets for a muscle into a single workout without the quality just falling apart. To make that much volume useful, you should spread it across more days. Now, we just took it as far as possible by doing a little bit every single day. So the real question is, does all that extra volume they're doing actually build more muscle, or does training every day interrupt recovery so much that rest actually wins. But so far it's the joints and tendons becoming the biggest limiter, which I did see coming. It's why from day 1 we had each person rotate exercises every day to avoid overusing the same tendons. So after a few days of Max lightening the weight and taking a break from leg extensions, he was good to go. And thankfully everyone's made it to day 30 injury-free. But before getting their MRI scans to see which side grew more, I wanted to first compare their final strength on each side.

13.

Can you do one more?

No. Oh, that's it.

13.

For both her biceps and triceps, her everyday side performed 3 more reps than her regular side. As for Brandon, how do you feel on your right side?

I feel pretty strong, actually.

2.

10. I'm gonna call it. 10?

You call it?

Are you sure?

Definitely less stamina on this side.

Surprisingly, all 3 subjects got noticeably stronger on their everyday side. But with daily training, you're also practicing the exercise every day. So that doesn't necessarily mean their muscle grew more, which is where our MRI scans come in handy. So everyone took 3 rest days before the scans to avoid the chance of any muscle swelling on their everyday side skewing the results. And then we sent the scans to Daniel Plotkin, one of the only researchers in the world experienced in measuring muscles from MRI scans. And he analyzed them blind, meaning he had no idea what we were actually testing or who he was measuring. And in fact, one participant's results confused him so much, he actually thought he made a mistake in their measurements. Let's start with Yolinda. The good news is that both sides did grow. The side that you did not train every single day That grew about 1% bigger. The side that you trained every day, it grew 3% bigger.

Wow, okay.

Which was against what you originally thought.

I think rest will make you recover.

That's locked in? That's locked in.

Halfway through, I started questioning my decision at the beginning. I was like, no way, like definitely the everyday arm.

Now let's move on to the most experienced of the 3 subjects, Max. After 30 days, Based on the MRI scans, 0% growth.

Ow.

Your right side, it did grow.

Oh, nice.

It grew about 2 to 3% bigger. Oh, wow.

Well, if it's a 2% growth in a month, after 12 months, that's 24%. Quarter of another leg.

The everyday training and the sacrifice and the time.

I don't think it's worth all that time though.

Now, although some of these differences may sound small, which they are, keep in mind that muscles grow extremely slow to begin with. In a study I designed and helped fund out of my local university, after almost 3 months of hard training, our subjects grew their muscles by about 15-20%, which equates to about 7-9% growth in 30 days. But our subjects were total newbies, never lifted before in their lives, and growth slows down by about half after every year of training. So for Yolanda and Max, who have been lifting weights for several years, the minimal growth we saw on each side is what I'd expect. Brandon, however, had the most room to grow. I need you to do a field test.

Just go like this.

The left side, which you trained 2 times per week, grew by 5%.

Not bad. 30 days, that's pretty good.

Which is very good. The right side grew almost 20%. What? When you look at his chest from the side, that's when you can see. And even though we didn't measure it, his triceps on his everyday side also seem to now be much bigger than his left. Sorry, Brandon. Now keep in mind, this is just a 3-person experiment. And while it is possible some muscles or even some people like Brandon just respond better to daily training, the fact that all 3 of them saw more growth on their everyday side, I don't think is coincidence. But before you start training your muscle every single day, I actually don't think that's the smartest way to apply this. You see, the daily training side won because we gave the muscle a small enough dose each day that it could still recover. But enough total work across the week to grow faster. After talking with Eric, he proposed a unique strategy that can get you a lot of the same benefit without requiring 7 days in the gym.

You can absolutely do what we call a specialization cycle. First thing, train those specialized muscles. So let's say you decided that you wanted to do a deltoid specialization. You'd start your lower body days and your upper body days doing some lateral raises or overhead press first for 2 to 3 sets and train them reasonably hard. Is your chest press going to suffer a little bit? Yes. Are your second iterations of shoulder press or lateral raises going to suffer a little bit? Yes. Will your delts grow more? Yes.

But there's one important rule: don't hammer the exact same exercise every time. Just like we did in this experiment, you want to pick two movements for that muscle and rotate them to avoid overusing the same tendons. So what exercises should you rotate between? Before I show you, if you don't want to figure out the programming yourself, our Built With Science app will take care of all that for you, building you a personalized workout and nutrition plan based on how your body's progressing every week. Just head to builtwithscience.com or scan this QR code right here to get 2 weeks free of our Built With Science coaching app. But if you want to do it yourself, here are the 2 exercises I'd recommend for each muscle. Thank you so much for watching, and I'll see you next time.