Resistance training exercises like Bulgarian split squats can help you strengthen certain muscles. Find out what these are.
From a high-level view, Bulgarian split squats mainly work your quadriceps (front thighs), gluteus maximus (butt), and hamstrings (back thighs).
Some of the secondary muscles you work with this exercise include your hip abductors (outer thighs), hip adductors (inner thighs), calves, and core muscles like your abs, obliques, and erector spinae.
The interesting part about Bulgarian split squats is that they do not always focus more on your quadriceps or always focus more on your glutes and hamstrings.
Your exact technique and relative strengths in these areas will influence what muscles you actually grow and strengthen the most by doing Bulgarian split squats.
Primary muscles worked with Bulgarian split squats
Bulgarian split squats are a compound leg exercise which means a variety of muscles have to work to some extent during the exercise.
At the same time, there are still a few muscles that have to move most of the resistance.
More specifically, Bulgarian split squats will mainly work your quadriceps (front thighs), gluteus maximus (butt), and hamstrings (back thighs).
Depending on your relative strengths in these muscles and your exact technique, Bulgarian split squats could grow and strengthen some or all of these.
Quadriceps (front thighs)
Your quadriceps are a group of four muscles in your front thighs. These have different functions but the main one for Bulgarian split squats is knee extension aka stretching the front leg.
This will be the main movement pushing your body upward. Especially if you keep your foot relatively close to the elevated object.
Gluteus maximus (butt)
The gluteus maximus is your main butt muscle. This area of your body is responsible for hip extension. In simpler words, this means moving your thighs back into one line with your upper body from a flexed position.
If you look carefully at how to do Bulgarian split squats, you will notice that the gluteus maximus will help your quadriceps raise your body.
Hamstrings (back thighs)
Your three hamstring muscles are located in the back of your thighs. Similar to the quadriceps, these have multiple functions.
In Bulgarian split squats, your hamstrings will mainly have to work to help the glutes with hip extension. This movement will generate part of the upward force.
Are Bulgarian split squats better for the glutes or quads?
If you look at how to do Bulgarian split squats below you will notice that both knee and hip extension will be responsible for the upward force.
Whether Bulgarian split squats are better for your glutes or quads will depend on your relative strengths in these areas and your exact technique.
For example, people with really strong glutes and weak quadriceps will likely grow and strengthen their quads with Bulgarian split squats.
Additionally, the glutes and hamstrings tend to be stronger than the quadriceps so you can say that Bulgarian split squats will generally be just a bit better for your quads.
That aside, you can find a few ways to modify your Bulgarian split squats below.

How to target glutes and hamstrings more in Bulgarian split squats
As mentioned, the glutes and hamstrings are responsible for the hip extension part of Bulgarian split squats.
To work these muscles more, you want to make it so you have to go through a larger hip extension motion under tension.
In practice, this will mean you want to put your foot farther away from the supper object and really tilt your upper body forward in the downward motion.
You likely want to pay some extra attention to keeping your spine straight in this more glute-focused Bulgarian split squat.
Is the Bulgarian split squat enough for working your glutes?
Bulgarian split squats already work your glutes a nice amount. Especially with the modifications above.
In turn, Bulgarian split squats can be enough for growing and strengthening your gluteus maximus.
You do want to keep in mind that you still need to do this exercise with enough resistance, repetitions, and sets to see results.
How to target quads more in Bulgarian split squats
To target your quads more in Bulgarian split squats you want to make it so the range of motion under tension of your knee flexion movement is bigger.
You can do this by putting your foot closer to the support object and really keeping your upper body straight up.
This will allow you to really fold your knee joint and in turn, work your quads a lot.
Secondary muscles worked with Bulgarian split squats
Bulgarian split squats also work a variety of secondary muscles to keep your body straight up, assist in the lift, and/or potentially hold any weights.
Some of these secondary muscles include your hip abductors (outer thighs), hip adductors (inner thighs), calves, and core muscles like your abs, obliques, and erector spinae.
If you do something like a dumbbell Bulgarian split squat, your forearm grip muscles and upper trapezius muscles will have to work a nice amount too.
On the other hand, something like a barbell on your upper back or one of the more glute-focused Bulgarian split squat variations will mostly work your erector spinae more.
Do Bulgarian split squats build size?
Bulgarian split squats are a resistance training exercise which means they can definitely help you build size.
Something you do want to keep in mind is that you still need to do the exercise with enough resistance, repetitions, and sets.
You will also need to give your body enough nutrients and rest to see muscle growth results.
One of the benefits of Bulgarian split squats is that the bodyweight version is already relatively challenging.
That means many people will be able to build muscle at home with this exercise.
At the same time, people who are more experienced with resistance training may need to do weighted Bulgarian split squats with a weighted vest, barbell, dumbbells, etc. to see results
Doing these more challenging variations at the right points in your training journey can also simply speed up your results.
Muscles worked Bulgarian split squat vs lunge
Lunges are a popular Bulgarian split squat alternative because it does not require any equipment at all.
The challenge with comparing these exercises in terms of what muscles they work is that your exact technique can vary a lot.
In turn, the muscle engagement in each exercise can look very different too.
For example, a regular lunge where you stay in place will focus a lot on your quadriceps. On the other hand, walking lunges can work your glutes and hamstrings a nice amount.
So both Bulgarian split squats and lunges will mainly work your quadriceps, glutes, and hamstrings.
Which of these muscles you will engage the most will depend on your choice of variation and exact exercise technique.
One thing you can say is that Bulgarian split squats tend to put more of your body weight on the front leg. In turn, the bodyweight version of this exercise will offer just a bit more training results.
That being said, you can resolve this relatively easily by adding weights to your workouts.
Are Bulgarian split squats or lunges better for training glutes?
Bulgarian split squats are not necessarily always better or worse than lunges for training your glutes. Both exercises have their quad-focused and glute-focused variations.