---
title: 'I Built The World''s Most Scientific Gym'
source: 'https://youtube.com/watch?v=U1zCyaQc91g'
video_id: 'U1zCyaQc91g'
date: 2026-06-28
duration_sec: 1187
---

# I Built The World's Most Scientific Gym

> Source: [I Built The World's Most Scientific Gym](https://youtube.com/watch?v=U1zCyaQc91g)

## Summary

Jeff Nippard unveils his custom-built 'Jeff Nippard Muscle Lab,' a personal gym and research facility. The space is divided into themed rooms for bodybuilding and strength training, plus a $300,000 lab for scientific muscle-growth experiments. The video aims to showcase the equipment and outline future research plans.

### Key Points

- **Gym Layout** [1:07] — The gym features a 'light side' for strength training and a 'dark side' for bodybuilding.
- **Variable Resistance Leg Extension** [2:15] — The Prime leg extension machine allows variable resistance profiles based on plate loading.
- **Calf Training** [4:40] — Donkey calf raise for deep gastrocnemius stretch; also has a standing calf raise machine.
- **Adjustable Seal Row** [6:59] — Seal row can be adjusted to focus on mid-back or lats.
- **Shoulder Press Side Delt Activation** [9:13] — EMG experiment showed high side delt activation during shoulder press, challenging expectations.
- **Reverse Pec Deck Modification** [10:29] — Modifying reverse pec deck by sitting sideways improves rear delt range of motion.
- **Lighting System** [12:45] — Customizable lighting system for optimal video thumbnails.
- **Research Equipment** [14:47] — Lab includes DEXA (0.5% error margin), ultrasound, EMG, and BIA machines.
- **Planned Experiments** [14:10] — Future experiments include twin diet study, steroid cessation study, and daily bicep training comparison.

### Conclusion

Jeff Nippard has created a personal gym and research facility to conduct scientific experiments on muscle growth, aiming to make exercise science more accessible and entertaining.

## Transcript

For the last two years, I've been
secretly building the most scientific
gym on the planet.
>> It's It's really a blank slate, bro.
This ceiling light is going to look so
sick. I think it's really unique. I
think it gives a like industrial like
techy type vibe. This is where I'll be
training myself, but it's not just for
lifting. It's actually a full-blown
muscle research facility. So, that now
in here, I'll be able to do my own
scientific experiments. I'm calling the
entire place the Jeff Nippard Muscle
Lab. And there are four rooms, plus a
lobby in the middle. There's a dark gym
with more of the bodybuilding machines,
a light gym with more of the strength
stuff. Room three is a new podcast room,
and then there's my personal favorite
room. This is where all the real science
will go down. And what's behind that
door cost me over $300,000.
And since it's the best part by far, I'm
going to save it for last. So, this is
the lobby. Got this custom art piece up
here on the wall. We got the custom JN
logo mat down here. And behind this door
is the dark side. Behind this door is
the light side. Let's check out the
light side first before we go in. This
is what it used to look like before.
This is gym gym side one. So, this is
going to be more of like a light toned
gym. So, it'll be a little bit brighter,
a little more white. And this is what it
looks like now.
[Music]
Before we start the tour, I just want to
make it clear that nothing in here was
gifted or sponsored. I just picked out
my favorite pieces from brands like
Alco, Atlantis, Prime, even an old
school precore machine. So, the first
thing you see when you walk in is the
deadlift platform. And now that I have
this gym, I have been getting back into
deadlifting more, but my main exercise
for my legs right now is right over here
around the corner, the pendulum squat.
So, if you guys have been watching me at
all, you know that I'm a huge fan of
pendulum squats and it's a really good
quad dominant squat because it is super
hard in that bottom part of the range of
motion. I have been using this flat out.
And also, check this out. I got my very
own Jeff Nipper Muscle Lab plates.
They're not all in yet, but uh I don't
know. I just love the look of these.
Speaking of the quads, this is a very,
very close second. So, this is a prime
leg extension machine. And the thing I
love about this one is that depending on
where you load these plates, you can
emphasize different aspects of the range
of motion. So if I load the plate down
here, okay, on the bottom, it's going to
feel really hard in the squeeze. So it's
going to get harder as you get to the
lockout. If you load it in the middle,
it's going to feel harder in the middle.
And then if you load it on the top, it's
going to feel hardest in the stretch.
So, when I do this, I normally load two
plates on top, two plates in the middle,
and that'll usually do me for around 10
reps. And not only that, this is the
only machine, the only leg extension
machine that I've seen that has this
deep of a knee angle. So, you can get
way deeper here than you can on any
other leg extension I've ever seen,
especially if you set the seat back.
This is hip abduction, hip adduction
machines. I actually had Jesse James
Weston here yesterday and I was telling
him that you can set the seat forward if
you want to get a little bit more of a
stretch. You can set the seat back if
you want to improve the angle of the
glute medius fibers a little bit better.
It's also super versatile. So, if you
set it in here, you can do your hip
abductions for the glutes. If you set it
out here, you can do your hip adductions
for the inner thighs. All right,
hamstrings. This is by far my favorite
lying leg curl machine on the planet.
And the reason for that is this angle
right here. This is pretty much the
closest to a seated leg curl that you
can get in a line leg curl. So it's
like, oh, why didn't you just get a
seated leg curl? Well, I did get a
seated leg curl, too. But there's
something about lying down, honestly, at
the start of a workout that just feels
better to me. And you get so deep on
this that it almost feels like your leg
is going to snap in half. And I mean
that in the best possible way. It is
just it is just an awesome machine. And
like with all Prime machines, depending
on where you set the cam, you can
overload different aspects of the range
of motion. I usually set it here in
between the max stretch setting and the
mid-range setting. All right, leg press.
So this is actually a fancy leg press.
So most leg presses are just linear. So,
you have this 45° angle and the weight
moves up and down in a straight line.
This one actually moves in an arc. It
just feels a lot more natural and uh I
can get nice and deep on this one. Super
smooth machine. Oh, I forgot to show
you. This is one of my favorite pieces,
donkey calf raise. This, I think, is an
underrated machine. It is a nostalgia
piece. This is famous in part because of
uh Arnold and his donkey calf raises.
But I was showing Jesse a few calf tips
on this yesterday. When you have that
bent hip position, you can take some of
the stress off your back, but yet you
still have a straight leg. And so you
can still get a super big stretch on the
gastro nemas. So yeah, absolutely love
the donkey calf. And then just to be
safe, you know, to be sure, I do also
have a standing calf raise machine. And
this one's really nice because this pad
is so grippy. And so you can just rotate
up and down on the balls of your feet
and you'll be super secure, super
stable, and just direct all that tension
into your calves. I was actually talking
to Larry Wheels earlier, and we're going
to get him in the actual lab that I'll
show you in a minute and do a full-blown
calf training study to see if we can
finally get his stubborn calves to grow
using science. Speaking of Larry Wheels,
we've got a full squat rack over here.
as a uh ex powerlifter. You know, I've
got to got to have some free weights.
But this
this is probably my number one glute
builder right now. I do like a 1 second
squeeze at the top of each rep because
the hip thrust is one of those rare
exercises where you're not really trying
to overload the stretch. You're really
just trying to engage your glutes. And
so, uh, yeah, squeeze at the top of all
your hip thrusts. All right. Obviously,
got to have a Smith machine in here. And
with a Smith machine, I'm really just
looking for two things. One is a
straight up and down bar path. So, I
personally am not a fan of the Smith
machines that have a angled bar path.
So, I wanted one that goes straight up
and down. And then other than that, I
just wanted one that was really smooth.
There's nothing worse than a Smith
machine that needs some oil. And I've
been using this one pretty much every
workout, too. You guys thought that was
it? That's just half. We still got the
dark side. So, come on over here.
You guys ready for the dark side? Let's
go.
[Music]
All right. So, like I said, this is the
more bodybuilding focus side. So, we've
got a little more dramatic down
lighting. I'm going to show you guys
something really sick with the lights in
a minute. But first, I'm going to start
with my favorite piece over here. So,
this, if you don't know, is a seal row.
This is one of those like old school
movements, but I just think it's so good
for smashing the midback. So, if you use
this horizontal angle, you can get so
much tension in your mid traps, in your
rhomboids, and your rear delts. But then
what I love about this machine in
particular, you can actually change this
angle. So, if I wanted to make it more
of a lat focused row, I could just bring
the bench up and focus on driving my
elbows down and slightly back. And
that's gonna absolutely light up my
lats. Also, check it out. We've got
custom dumbbells with Jeff Nipper Muscle
Lab on them. I just love these. A very,
very close runner up for back training
in this gym would be the prime chest
supported row. And so, just like with
the leg extension, depending on where
you load the plates, you can overload
different aspects of the range of
motion. Um, so if you load the plates on
the bottom, you can overload the
squeeze. Load them in the middle, load
that mid part of the range, load them up
on top, and you'll get more tension in
the stretch. Absolutely love this one.
Over here, we've got another uh tea bar
row. I'm still trying to find a home for
this one, but um I don't know, there's
something about like the angle and the
size of this. The way that the handles
flare out, it just works super well for
my body right here. So, most people
think this is a lower back exercise,
right? After all, it is called a uh 45°
lower back extension, but I actually
think this is much better as a glute
exercise. And so, all you need to do to
turn this into a fantastic glute builder
is round your back. And that'll force
your glutes to handle more of the hip
extension. Like, I've been doing this
every week on one of my leg days. And
I'll just do 12 to 15 reps with a plate
held to my chest. And you will feel the
craziest mind muscle connection with
your glutes doing this. So, if you're
sleeping on the 45 degree back extension
for glute growth, it's time to wake up.
Let me show you guys some shoulder
stuff. Let's go here first. So, this is
a shoulder press machine. And some of
you guys might be wondering, "Well,
Jeff, why did you get a shoulder press
machine? Doesn't that only hit your
front delts? And don't your front delts
get all the work they need from bench
press? And shouldn't you focus more on
your side delts?" Well, the other day I
busted out one of the many new
scientific tools from the research room
with my friend Will, where we hooked
electrodes up to his front delts, side
delts, and rear delts, and measured
muscle activation of all three heads on
my new shoulder press machine. The
results really surprised me. What we
found was super high activation in the
front delts, as you'd expect, super low
activation in the rear delts, as you'd
expect, but also super high activation
in the side delts.
>> You actually had more lateral than front
on the shoulder press.
>> What?
>> That's insane cuz as soon as I stopped
the set, I'm like my side delts pumped.
>> Yeah.
>> Then I hooked the left pros up to myself
and got my own measurements and found
the exact same thing. So, I'm not saying
that that's conclusive by any means, but
it seems that at least for Will and me,
a shoulder press is not just a front
delt exercise. It seems to also really
activate the side delts at least more
than what most people think. So, I'm
actually a fan of including a vertical
press. Also for shoulders, I've got this
standing Atlantis lateral raise machine
over here. This is one of my favorites.
Super smooth, such a great range of
motion, and just a really good
alternative to cables or dumbbells. Will
and I also did a little experiment for
the rear delts. So, we came over here
and we did reverse pec deck, but if you
guys are regular viewers, you'll know
that I don't love to do these facing the
machine like this. I prefer to sit more
to the side and that way I can get such
a better range of motion for my rear
delts. You know, if if you face the
machine, you're really only able to do
half reps because the full range of
motion for your rear delts is from here
all the way back to here. And so if
you're facing the machine, you're only
getting this aspect. It would be like
doing bicep curls only in the top half
and completely cutting out the bottom.
So that's how I modify this. And when we
did that and we measured muscle
activation, we did see super high rear
delt activation as you'd expect. But
also, I found it interesting. There was
very little side delt activation on this
and basically no front delt activation.
So, yeah, really good rear delt
isolation exercise if you're looking to
bring up your rear delts. Okay, we've
got a lat pull down. Pretty standard
here. Really smooth. Over here, we've
got a seated cable row. And what I like
about this one is this distance right
here. What that allows me to do is get a
super deep stretch on my lats. Over
here, back to chest. So, this is my
favorite chest press machine on the
planet. Actually call this the Phil
Heath machine because I remember when I
was first getting into bodybuilding, I
saw a video of Phil Heath using this
machine. And ever since then, I've just
been convinced that it's the best
machine for the chest. And to make it a
little bit more effective, I actually
added these fat grips just so I can get
a little extra range of motion at the
bottom. But what I might do is uh
actually modify this seat to bring it
forward a little bit more because I feel
like I could get just a little bit
deeper. But when it comes to smoothness,
you just Yeah, you just can't beat the
hammer strength chest press, man. So
good. All right, couple more things and
then I'm going to show you guys
something I'm also super excited about.
Okay, over here we've got a treadmill.
Whatever.
This is I think honestly it's the best
cable machine that I could find. Um,
this is called the Nautilus Human Sport
Freedom Trainer. And the reason I think
it's so good is that it's just so
versatile. So, you can set the cables to
any height you want. You can move them
in or out. Um, you can do any kind of
exercise from low, from high. Um, and
this one I use every single upper body
workout. But, you know what? I didn't
show you guys yet. The lighting in here.
Check this out. We honestly put so much
work into the lighting in here because I
just want it to look as cool as possible
on camera. And so we have a full panel
in here where we can adjust all the
lights individually and every single
light has its own dimmer. Let's just say
we wanted to create a spotlighting
effect for just like maximum shadows on
the muscle. We could turn off all the
headlights and then every single
spotlight in here is individually
controlled. So I could turn them all off
except for one. And this is what I'm
going to call the thumbnail lighting.
Check this out.
I just got 5% body fat leaner.
It's actually insane the difference that
lighting can make. But that's not it. I
still need to show you guys the real
purpose behind this entire project. Um,
this is going to be the lab. Probably
like some kind of muscle mannequin right
here. And then I think I'm going to put
a sign
that says Jeff Nippard Muscle Lab. This
room over here is the Jeff Nippard
Muscle Lab.
There are so many fitness questions I
want to answer here. Like, what if I
took a set of twins and I had one twin
eat a junk food only diet and the other
twin eat a clean food only diet? What
would happen to their body fat and their
blood work? Or how about this? What if I
took an enhanced bodybuilder and told
them to stop taking steroids for 6
months, but keep their training and diet
exactly the same? How much muscle would
they lose? I'm also excited to test
things out on myself. Right now, I'm
testing if I can get to single digits
body fat and actually maintain it all
year without going crazy. And I'm
measuring my body fat, muscle, hormone
levels, and everything else using the
tools in this lab. This is a
top-of-the-line DEXA machine for
measuring body fat and lean mass. Some
DEXAs are less precise, but this one has
an error margin of around 0.5%.
At my latest check-in for my fat loss
experiment, my DEXA scan came back with
a body fat percentage of 10.3%.
So, if I lose anything more than 0.5%
body fat from here, this DEXA will be
able to accurately pick it up. And DEXA
is great for tracking fat loss, but for
the muscle building experiments I want
to do, it's not quite accurate enough.
So, I also got this brand new ultrasound
machine, which can measure muscle
thickness directly. I want to do an arm
experiment where I train one bicep
normally twice a week, but I train my
other bicep every single day for 30
days. Using the ultrasound, I'll be able
to measure down to the millimeter which
arm grows better. So, if you take this
ultrasound probe, gel it up, and put it
on the muscle, it'll show you exactly
what's happening on the inside and how
well it's growing over time. So, up here
on top, there's a layer of skin and
there's a thin layer of fat. And all of
this is the actual biceps muscle tissue.
And below that is the bone. We're going
to be able to do really high quality
studies that I definitely want to get
peer-reviewed and published. This isn't
just for experiments on YouTube. I think
that there are so many gaps in the
research and there are so many studies
that have flaws with them that I just
want to make my own. So now I can do
that. I have the ultrasound. I have the
DEXA machine. I can get however many
subjects I can recruit to come in here.
Bro, it's going to be it's going to be
peer-reviewed. It's going to go in
scientific journals. It's like it's it's
going to be like doing a study but just
like this is the university, you know.
But if I'm being honest, pushing the
scientific field forward wasn't my main
motivation for building this facility.
My main motivation is to make
highquality science more accessible and
entertaining. The range of motion study
that I did last year in New York
comparing full range of motion to
lengthen partials was actually the first
ever exercise science study where the
researchers were allowed to film the
subjects. And even with that permission,
we still had to blur out their faces.
And since I'm not formally affiliated
with the university, I still wasn't able
to film them myself. So that was a bit
frustrating because I felt like I
couldn't showcase exactly what the
subjects were doing as well as I wanted
to. Here, we're going to be able to film
every single subject in every study that
I do, show you exactly what they're
doing, show you exactly the gains they
make. Like just imagine how much more
that's going to help people connect with
the science when you can actually see
the subjects going through the protocol.
Like that's never been done in exercise
science ever. And we're going to be able
to do that here. I also want to do some
really big studies in here with hundreds
of subjects because a legitimate problem
with a lot of training studies is that
they have really small sample sizes.
Like it's normal for studies to only
have eight or 10 subjects. So, if we get
a load of people in here and we just
need to grab a quick and dirty snapshot,
we can use this BIA machine. Yeah, I'll
definitely use the DEXA more, but BIA
can measure body comp in about 1 minute,
whereas DEXA takes about 20 to 30
minutes. And BIA is still pretty good at
tracking changes. And I'm super excited
about this EMG machine. I want to run an
EMG validation study to see if higher
electrical activity is actually
predictive of hypertrophy over the long
term because that's not something we
really know yet. If it is, this will be
really useful for comparing exercises.
And at this point, you may be wondering
how I'm funding all this. The DEXA
machine alone costs $200,000. And it's
honestly all possible because of you
guys. Nothing in the lab or in the gym
is sponsored or gifted. It was 100%
funded through the training programs
that you guys run on jeffnnipper.com and
through any of you who use MacroFactor,
which if you don't know is my smart
nutrition app that uses science-based
algorithms to adjust your diet to your
specific metabolism, just like a coach
would, but for a tiny fraction of the
cost. All you need to do is log your
weight and track what you eat, and the
app will take care of the rest. I've
been using it every day on my cut so
far. And it's taken me from over 20%
body fat down to just over 10% body fat
now. And I'll be honest, it's made the
entire dieting process super simple.
When you track your macros, you can
still be flexible and enjoy life without
having to compromise your goals. We have
over 350,000 users and an amazing online
community that can help you out with
recipes, answer any questions you might
have, and keep you accountable. So, go
to the App Store or Google Play,
download a free trial, and input code
Jeff to get two weeks for free. It's
been so hard trying to keep this a
secret for the last 2 years because it's
been so much work and also so much
excitement. And I almost forgot, the
final room is the Jeff Nippard podcast.
So, my podcast is officially live. I did
my first episode with my brother Brad.
You guys might remember him from the
experiment that we did together where we
both trained as perfectly as we possibly
could for a full year. I'll put a link
to that over here next to my head if you
guys want to check it out. Don't forget
to subscribe to this channel. Leave me a
like if you enjoyed the video.