When you have “build a strong and powerful butt” written at the top of your list of fitness goals, tried-and-true glute exercises such as squats, deadlifts, and lunges will likely be the backbone of your workout programming.
While those moves will surely help you get the job done, there are other exercises you may want to bake into your routine as well. Enter: The Kas glute bridge, a booty-building exercise that’s essentially an isolated, controlled hip thrust, according to Morit Summers, a certified personal trainer and the owner of Form Fitness Brooklyn in New York. (BTW, the move is named after fitness coach Kassem Hanson, who recently popularized it, but it’s actually not a brand-new exercise, says Summers.)
Here, Summers breaks down all the benefits the Kas glute bridge has to offer. Plus, she shares exactly how it differs from the standard hip thrust and how to perform and modify the exercise based on your fitness level.
How to Do the Kas Glute Bridge
There's not much difference between the Kas glute bridge vs. hip thrust setup — your shoulder blades are resting on a bench and you lift your hips toward the ceiling — but the Kas glute bridge involves a smaller range of motion and amount of power, says Summers. "When you do a full hip thrust, you're allowing your body to fold and use more power to drive the weight up, and you can do seemingly much bigger loads," she explains. "With the Kas glute bridge, you're going into a much shorter range of motion and targeting just the glutes, and you're not allowing the body to be involved in the same way."
In other words, you lift and lower your hips just a few inches in a slow, controlled manner in a Kas glute bridge. In a standard hip thrust, however, you lower your butt toward the floor and explosively drive your hips up toward the ceiling. (
A. Sit on the floor with center of shoulder blades resting against a bench or box, knees bent and feet planted on the floor slightly wider than hip-width apart. Place an (optional) barbell or dumbbell in hip crease and hold with both hands.
B. Keeping lower back flat, chin tucked, and gaze forward, engage glutes, push through heels, and raise the barbell to the ceiling by extending hips to reach the starting position. Knees should be in line with heels and bent at 90-degree angles and body should form a straight line from shoulders to knees.
C. Keeping lower back flat and knees stable, slowly lower hips two to three inches. Then, push through heels and slowly raise the barbell by extending hips, making sure to use glutes rather than back to perform the movement.
D. Continue lifting hips until body forms a straight line from shoulders to knees to return to the starting position.
The Key Kas Glute Bridge Benefits
As you've probably inferred at this point, Kas glute bridges put your booty to the test. Below, details on how, exactly, it can do your bum some good.
Encourages Muscle Growth Through Prolonged Time Under Tension
Kas glute bridges are typically performed at a slower speed than traditional hip thrusts, as you’re not trying to generate as much power, says Summers. With that in mind, your muscles spend more time under tension, which refers to the amount of time they’re contracting against an external resistance (think: weights), according to the American Council on Exercise (ACE). Increasing time under tension causes more muscle breakdown and metabolic fatigue and, with proper recovery, can lead to more muscle growth, according to ACE. (
While you can perform slow hip thrusts to increase time under tension, the Kas glute bridge may still have a small leg up. As you lower down to the floor in a hip thrust, you'll inevitably lose some tension in the glutes, while the Kas glute bridge has a small enough range of motion that your glutes are under tension throughout the entire movement, says Summers.
Increases Strength with the Option to Add a Load
Both the Kas glute bridge and the traditional glute bridge — which you perform while lying on the floor — are performed with a smaller range of motion than a hip thrust. But unlike the floor-based exercise, the Kas glute bridge can easily be loaded, says Summers. FTR, it is possible to load a basic glute bridge by placing a dumbbell or barbell on the waist, but it’s often difficult to hold in place and can be distracting while powering through reps, she explains. “Doing the Kas glute bridge from a bench, a box, or anything that you’re able to put yourself on makes it much easier to load,” says Summers.
Kas Glute Bridge Muscles Worked
Since the range of motion is shorter in a Kas glute bridge than a hip thrust, you’ll end up using primarily your butt muscles, particularly the gluteus maximus, to extend the hips and lift the barbell up, says Summers. As a result, the exercise helps build strong glute muscles, which are needed to stabilize your pelvis and ensure the proper functioning of your lower body, according to ACE. Specifically, if your glutes are weak, you may compensate with other muscles during movements, such as the hamstrings and quadriceps, which can ultimately lead to injury, according to ACE.
This glute engagement is also a key difference between the Kas glute bridge and traditional hip thrust. "The Kas glute bridge is supposed to just be glutes," says Summers. "…With the hip thrust, because you're adding this element of power and more motion, sometimes people can't actually feel their glutes working — they'll feel their quads and their hamstrings. And they're really just generating power and force through the ground." An isolated Kas glute bridge, however, forces your booty to do the bulk of the work.
That said, your core — which protects the spine — does still get involved in the movement. Specifically, the core provides stability and prevents your lower back from excessively arching, which can lead to back pain and injury, during most exercises. And that includes the moves in which you press weight overhead or have a heavy weight sitting on your body, such as a hip thrust or Kas glute bridge, Laura Miranda, D.P.T., C.S.C.S., a physical therapist in New York, previously told Shape.
Kas Glute Bridge Exercise Variations
Whether you're a hip-thrust newbie, in the mood to tone down your workout, or want to take things up a notch, you can modify the Kas glute bridge accordingly.
Modify with a Standard Glute Bridge
If the Kas glute bridge feels a bit too tough, try performing the move with just your bodyweight or scaling down to a glute bridge on the floor, suggests Summers. Mastering the traditional glute bridge helps you practice the proper pelvic tilting and understand how the hips move, she says. Then, you can progress to a single-leg glute bridge and finally give a Kas glute bridge a shot, she says.
Advance with Weights or a Single-Leg Variation
Once you’ve mastered the Kas glute bridge and are ready for another challenge, you can level up the exercise by adding heavier weights, such as barbells, dumbbells, or kettlebells, into the mix, says Summers. You can also try a single-leg variation, in which you raise one foot off the ground and slightly bend the knee of your lifted leg. While Summers has yet to test this alternative herself, “you can absolutely do a single-leg hip thrust and you can do a single-leg bridge on the ground, so the answer is likely yes, you can do a single-leg Kas glute bridge…just based on biomechanics and how exercises work,” she says. Just remember to focus on extending the hip via the glutes and avoid relying on your lower back to thrust the weight (if you’re using one) up toward the ceiling, she suggests.
Common Kas Glute Bridge Mistakes
Whether you’re doing a traditional glute bridge, basic hip thrust, or the Kas glute bridge, you’ll want to tuck your tailbone and prevent your lower back from arching (aka creating an anterior pelvic tilt) — a common mistake that can end in injury, Hannah Davis, C.S.C.S., a certified personal trainer and the creator of Body By Hannah, previously told Shape. “We want to be extending from the hips and not the lower back,” says Summers.
It's also important to keep your knees in line with your ankles and parallel with your hips, adds Summers. "That's just so you are isolating at the hip and not letting the body move too far," she says, which ensures the exercise targets the glutes.
How to Add the Kas Glute Bridge to Your Routine
When you feel confident and ready to tackle a Kas glute bridge, start with just your bodyweight or a light dumbbell to perfect your form, recommends Summers. “I say this for every exercise, but start light and work your way up,” she says. To get the booty-building benefits, consider incorporating the Kas glute bridge into your programming about once a week, says Summers. “With the Kas bridge, you aren’t going for super heavy — you are going for hypertrophy, so [increasing muscle] strength and growth,” she adds. “I’d recommend anywhere from three to five sets for 10 to 20 repetitions. ” Of course, the exact reps and sets required to see gains will vary from person to person, depending on fitness level, abilities, and goals, so chat with a trainer for individualized guidance.
You'll also want to check in with a professional and take a cautious approach to the Kas glute bridge (and hip thrusts and floor glute bridges, BTW) if you have any spinal, disc, or nerve issues in order to avoid potential injury, says Summers. "It's not that you can't do these things — it's that you have to be really conscious about your positions," she adds. "Doing heavy, heavy hip thrusts, which can very easily throw you out of a good position, is not a good idea. The Kas glute bridge is a bit more focused on the position [re: the movement is more controlled] so it can be a bit safer." That said, there's no harm in playing it safe and speaking with an expert before you tackle the exercise.