Your Butt Muscles Have Arrived

On the inside, no matter what anyone’s butt looks like on the outside, they all look pretty much the same. Are you ready to learn about the anatomy of the butt muscle? The three primary butt muscles that make up your glutes are as follows:

The smallest of the glute muscles, the gluteus minimus, is located directly underneath the gluteus medius. It turns your leg inward and abducts it (moving it away from the body’s centre).

Gluteus medius: The Gluteus medius is a pork chop-shaped muscle that rests on the exterior of your pelvis. It abducts and turns your leg inward, just like the gluteus minimus.

Gluteus maximus (Gluteus maximus): The Maximus is the largest muscle in your body, as its name suggests. Its role is to extend your hip and spin your leg outward (think of what happens in your hip during a squat’s upward action).

The gluteus maximus receives all the attention, but the medius and minimus, in addition to those listed above, play a vital role. “They’re in charge of stabilising your pelvis when you walk or are off-balance,” Dr. Herrera explains. Yes, your glute med and min just kicked in as you stood up and balanced on one leg.

Glute Shape & Genetics

The Maximus extends diagonally from the top of the pelvis to the femur. The iliotibial band on the outside of the upper thigh attaches to the same spots on everyone’s bones.

However, if you have a lofty pelvis, “you may have a longer, squarer form to your posterior,” explains Kimberly Topp, PhD, chair of the University of California, San Francisco’s physical therapy department. “You may have a more horizontal position of the butt muscles if you have a broad pelvis.” Your buns may seem more elevated if your back is more curved.

Translation: You can work on your glutes to adjust their size and shape (later on), but some people have naturally rounded gluteal muscles, while others have different-shaped butt muscles.

So, how much of your butt form is influenced by genetics? According to Dr Marango, up to 70% of the total state of the body (and hence the shape of your buttocks) is inherited. “Anything outside your genetic code, such as nutrition, exercise, sleep, posture, and so on, will impact the rest.” You can thank our gender for the fact that women have more posterior padding than males, and you can thank Mom and Dad for the location of that padding.

However, no matter what form your butt is in when you start, it will change with time. According to Matthew P. Reed, PhD, a research associate professor at the University of Michigan in Ann Arbor who studies body shape, a woman of 50 has a flatter butt profile than a woman half her age because shifting hormone levels post-menopause signal the body to store fat in the belly rather than the buns. “There will be less fat on the side of the buttocks and more on the iliac crest at the top of the pelvis,” he explains. “That’s why clothes don’t fit the same as they used to as you age.”

What’s the good news? By strengthening and maintaining powerful butt muscles, you can give gravity a run for its money. (By the way, Kim K’s trainer shares her finest barbell squat tips here.)

How to Develop More Powerful Butt Muscles

If you want bigger or rounder glutes, Topp explains, “you have a lot of options to modify the contour of your buttocks if you’re prepared to spend the time on it.”

The gluteus maximus comprises a mix of fast-twitch muscle fibres—those that fire quickly and are used for bursts of speed or power—and slow-twitch muscle fibres, which do the heavy lifting during aerobic exercises. Research indicates that the gluteus medius and minimus are largely slow-twitch muscles. This means that both high-load, low-rep strength training, such as heavy-weight squats (to target the fast-twitch muscles), and low-load, high-rep endurance training, such as jogging and stair climbing, can benefit the butt muscles (to work slow-twitch muscles). However, there are several non-squat strength routines that are essential for developing stronger glutes, and it’s also a good idea to include glute activation drills at the start of your workouts to ensure that all muscles are firing.