All of you have glorious butts or more specifically gloriously large butts because humans have the biggest butts in the animal kingdom. But why is that? Is it fat? Is it muscle? Or is it something else? Well, today we're going to answer this allimportant question by looking at the cadaavver dissections as well as by discussing how the butt evolved in humans. We'll also talk about why certain muscles that make up the butt are so functionally important and discuss how to strengthen these muscles to help prevent some dysfunctions that can occur from sitting too much. It's going to be a cheeky one. So, let's jump into this anatomical awesomeness. First off, let's clarify. When I say humans have the biggest, most glorious butts, I'm talking about butt to body size ratio. Sure, an elephant's rear is massive in absolute terms, but if you scaled up a human to elephant size, our glutes would show that elephant what a real butt looks like. And if you compare it to our primate cousins, like chimps or gorillas, our beehinds are going to be proportionally huge compared to them as well. So, what's going on here? Why are our butts so massive? Well, to answer this question, we need to start with the basics. What exactly is the butt? There are plenty of slang terms out there like booty, bum, dairy, rear, tush, and more. But anatomically, we call this the glutial region or buttocks. It's made up of skin, connective tissue, fat, and muscles. And to really see this, let's take a look at a real human cadaavver dissection. So, here you are looking at the left side. And starting from the outside or the most superficial layers, we'll see the skin made up of the epidermis and dermis, which you can see I'm pinching both of those together here. And you can also see that this doesn't add much bulk to the region. But the next layer down is the hypodermis or the subcutaneous layer. And this is made up of atapost tissue or fat. And this is often the part of the butt that people assume that I'm talking about when I say humans have big butts. But that's not actually what I'm referring to because the hypodermis or this fatty layer can vary significantly from person to person. Like on this body, it's only about a half inch thick, but it can be up to several inches thick on other people and everywhere in between. So what I'm saying is that humans are not unique in having butt fat. What they are unique with is what's underneath the fat, and that is this muscle called the glutius maximus. All of you, regardless of the amount of butt fat that you have, have a glorious glutius maximus underneath, which to give you a more zoomed out view of this muscle, you can see the right glutius maximus and the left glutius maximus on this other body. But by volume and mass, this is often the largest muscle in the human body. It's thick, powerful, and gives the glutial region its shape and size. But why is it so massive in humans? Well, that brings us to the evolution and function of the glutius maximus. But before we get into the evolution and function of the glutius maximus, let's take a moment to talk about an awesome tool that can give you insights on your muscle mass, atapose tissue, as well as other health insights, and that is the Hume Health Body Pod. This is not just some bathroom scale. It's a clinical grade body analyzer that gives you much more information than just your weight. The Body Pod uses bioelect electrical impedance analysis to scan and deliver over 45 metrics. Things like skeletal muscle mass, body fat percentage, hydration levels, and metabolic age to name a few. It even breaks that data down into regions, which helped me to realize that I have some mild imbalances in muscle mass between my right and left side. So, you could definitely use this to address these muscular imbalances. Now, admittedly, I have been skeptical about at home devices like this in the past that claim they are 98% accurate like the Body Pod, but I had body composition tests done at a lab around the same time I started using the Body Pod, and the results were nearly the same. So, I've been using it for weeks now, and I've been logging consistent weigh-ins, syncing my sleep and workouts, and even setting milestone goals that I can track in the app. And as a bonus, The Body Pod is HSA and FSA eligible. So, if you want to know more about your own anatomy, click the link in the description to check out the Body Pod and use our coupon code the anatomy lab to start optimizing your health routine today. And now, let's get back to why humans have big butts. To understand why our butts are so big, we need to look at our skeleton and how we move. The glutius maximus attaches from the illium and the sacrum down to the femur and even inserts into the IT band. This positioning allows this muscle to be the powerhouse of a very important movement called hip extension. Hip extension is pulling your thigh backwards, which looks like this. Coming up would be hip flexion, creating that crease, and moving back in the opposite direction would be hip extension. Now, most often this occurs with a knee bend. Say like when you're climbing the stairs, you would extend your hip to stand up or maybe you're hiking up a steep hill and definitely occurs when you're say standing up from a squat. That would extend your hip on the way up. But here's where the evolutionary story comes in. Humans are bipedal. We walk on two legs. Unlike quadripeds, such as cats and dogs who stay in a flexed hip position, we stay fully upright. Meaning our glutius maximus is constantly engaged or buzzing just to keep our hip in that extended position. Or in other words, to keep us upright so we don't topple forward. And this becomes even more important when we apply this to walking, running, or sprinting. When your foot plants, your body's or your upper body's momentum wants to pitch you forward, but your glutius maximus is like uh-uh and contracts and pulls upright, keeping the pelvis in alignment and keeping you upright and stabilizing you from, like I said, falling forward. In our ancestors, this was crucial for endurance, hunting, climbing, and efficiently doing bipeedal locomotion. Fossils show that while upright posture emerged earlier in hominids around four to six million years ago, the glute max really started to grow disproportionately as species like Homo erectus refined bipedalism around 2 million years ago. And again, if you compare to one of our closest ancestors, chimpanzees have much smaller glutes because they knuckle walk and don't need that constant extension power. And here's a fun random fact. Sitting a lot in modern life can weaken these muscles leading to what some refer to as dead butt syndrome or also sometimes referred to as glutial amnesia where these muscles become weakened or almost forget to fire properly. And deadb butt syndrome or glutial amnesia isn't technically a clinical diagnosis but more of a phrase discussed with physical therapists and athletic trainers to talk about some of the dysfunctions of the glutial muscles that can occur with excessive sitting. But this is why exercising and activating or using the glutes in the way that they were meant to be used is so important. But we'll get more into that in just a second because I do want to mention that the glutius maximus isn't alone in helping us move the hip properly. There are also smaller helpers like the glutius medius and glutius minimus muscles. And one of the main functions of these two muscles is to perform hip abduction which looks like this. Moving the thigh or the leg away from the midline of the body. And I can actually even show you on with these two bones here in this hip joint. This would look like so I'll try to do it at the same time. Yes. Yes. And just because we didn't show you hip extension would be coming back like so. Now another thing that we want to think about here is from a functional standpoint I can't imagine our cave men and cave women ancestors waking up each morning and being like we need to work out our glutius medius and glutius minimus. Let's do this. and in their caves they're just like, "Yeah, yeah, can you feel that burden?" No, they weren't doing that. So, how are these muscles important from a functional standpoint? Well, it comes again with walking and running, especially during the phase when one leg is off the ground. When we have one leg off the ground, because of gravity, your pelvis actually wants to dip downward. And that dipping would actually cause adduction of this hip. But because we don't want to have our pelvis just dip down and have this weird dysfunctional walking glutius medius and glutius minimus contract and actually pull us back into abduction and keep our pelvis in alignment and stop our pelvis from dipping down every time we take a step. Now I remember years ago I was on this single leg squat kick and this is before I took anatomy and did my medical training. So, I was a little surprised with what happened with this, but I was thinking, I'm going to build my quads with these single leg squats and have great balance. And I thought the next day that my quads were going to be so sore. But the next day, my quads didn't even care. But my side cheek, my glutius medius, and glutius minimus were so sore from all the extra contracting they had to do to stop my pelvis from dipping down with all those single squats that I performed. So clearly the glutius maximus, glutius medius and glutius minimus are very important from a functional standpoint. And because we are in this bipeedal position, the glutius maximus is quite developed just to hold us upright all the time. And this results in us having gloriously large butts proportionally compared to other animals. And weak glutes can cause issues like knee pain, low back pain, and even poor posture. And obviously in sports and fitness, strong glutes boost power for things like explosive jumps, sprints, or heavy lifts. So it is definitely important for us to maintain strong and functional glutes, especially if you have a job that has you sitting for extended periods of time. So let's just mention a few bang forbuck glute exercises. And most often bang forbuck exercises are going to include compound movements that mobilize more than one joint and therefore activate multiple muscle groups. And if you're really new to this, you can start with body weight. And as you get stronger and fitter, you can add weights or more load and or reps over time. And so, first we have deadlifts. This could be conventional or Romanian. These allow you to get that full extension at the top of the movement while strengthening other important posterior chain muscles such as the hamstrings and even the back extensors, which will also help with core stability. Second, we have squats. Whether barbell, goblet, or body weight, they force hip extension under load. And depth is important with this. If you're only doing something like quarter squats, that's not going to activate the glute max nearly as much as say a full squat. And third, we have hip thrusts. These are excellent for firing into the glutius maximus. You can start with no weight and then eventually add a barbell as you get stronger. And we can't forget about those unilateral exercises such as lunges, step-ups, or even those single leg squats. This will help to isolate and fix imbalances between each side as well as let the glutius medius and minimus know that you haven't forgotten about them. Now, how often you do these exercises can vary quite a bit depending on your goals and if you're participating in other types of exercises or sports. Like somebody who's doing a lot of running or training for a marathon probably isn't going to do three big leg days per week. But I think a pretty good rule of thumb for everyone would be at least one day a week at the minimum. However, with most of my patients who just want a generalized fitness plan where they get a good combo of cardio and strength training, I often try to have them start with alternating cardio and strength training days. For example, Monday, Wednesday, Friday might be their cardio days where they do the majority of their cardio in zone 2 with a mixture or throwing in some highintensity interval days. And then Tuesday, Thursday, Saturday would be their strength training days. Now again, you can create all sorts of effective fitness plans, but one that's pretty basic is doing an upper lower split. Meaning on Tuesday for their strength training day, they would do their upper body. Then on Thursday, they would do lower body. And then on Saturday, they'd go back to upper body. But then the next week, Tuesday would be lower body. Thursday would be upper body. And then Saturday back to lower body. So what you're seeing there is one week you're getting two upper body days and one lower body day. And then the next week you're getting two lower body days and one upper body day. That's a pretty good mixture and enough stimulus to make growth and strength gains. And when we're talking about growth and strength, there's kind of a nice little happy medium as far as reps. When you're going like from six to 10 reps, three to four sets per exercise, that's a really good place to start to kind of get some benefits with strength as well as a little bit of an increase in muscular size. And again, you can tweak all this depending on your goals. But hopefully that gives you a good place to start from with a strength training routine and gives you enough knowledge to understand why you have a gloriously large butt compared to other animals. Thanks for watching and supporting the channel everyone. If you're interested in that Hume Health Body Pod, check out the link in the description below. And of course, we'll see you in the next video.