Stair climbers and steppers definitely offer intense workouts. During these, you work a few skeletal muscles in nice amounts.
More specifically, some of the main muscles you work with climbers and steppers are your quadriceps (front thighs), glutes (butt), hamstrings (back thighs), hip flexors (front hips), and calves.
Besides that, your hip abductors (outer thigh), hip adductors (inner thigh), and core muscles like your abs, obliques, and erector spinae have to work to some extent too.
That being said, something important to note is that if you can do more than 50 steps per leg, you will likely not build any muscle with stair climbers.
Since the leg muscles you work are relatively strong, this will often be the case.
On the other hand, it is worth mentioning that engaging your muscles can still offer benefits even if you don’t actually grow them.
This can still improve muscle endurance, make your muscles healthier, and slow down muscle degradation.
Primary muscles worked with stair climbers and steppers
When using stair climbers and steppers there are a lot of movements going on. In turn, this requires some work from a variety of muscles.
Even so, only a few of these will have to exert most of the force to move the steps down and your body up.
More specifically, the main muscles worked while exercising on stair climbers and steppers are your glutes, hamstrings, hip flexors, quadriceps, and calves.
You can find where these muscles are and what they do in the sections below.
Quadriceps (front thighs)
The quadriceps are a group of muscles located in your front thighs.
To get more specific, these muscles include the vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris (also a hip flexor).
The main function of your quadriceps while using stair climbers and steppers is knee extension aka stretching your legs.
Together with some of the other muscles you work, knee extension is responsible for pushing the stair climber steps down and moving your body up.
The closer your steps are to your body, the more the force you generate will come from your quadriceps.
The glutes are a category of muscles around your butt. These include the gluteus maximus, gluteus medius, and gluteus minimus
While using stair climbers and steppers, it will mostly be the gluteus maximus that has to work.
This muscle is responsible for hip extension which means moving your thighs down and back.
Hip extension will be a big driver behind pushing the pedals of the stair climber machines down and lifting your body up.
Something important to note is that the glutes are very strong muscles. If you want to grow and strengthen these, you will need a lot of resistance.
That means stair climber and stepper workouts alone are typically not enough for these goals. Potentially even for people who are new to exercising.
Hamstrings (back thighs)
Your hamstrings are a group of three muscles in the back of your thighs. These three muscles are named the biceps femoris, semitendinosus, and semimembranosus.
This muscle group has different functions. While using a stair climber, your hamstrings will mainly help the gluteus maximus extend your hips.
In simpler words, your hamstrings help your butt muscles push down the pedals and push your body up.
Similar to your glutes, your hamstrings are relatively strong. That means stair climbers and steppers will likely not challenge these muscles enough to cause growth.
Hip flexors (front hips)
The hip flexors are another group of muscles. These muscles include the rectus femoris, iliacus, psoas, iliocapsularis, and sartorius.
These hip flexor muscles are responsible for moving your thighs forward and up. As you can expect, this movement is called hip flexion.
Before you can push the pedals of the stair climbers and steppers down, you have to bring your thighs up. That means your hip flexors have to work to some extent in each step you take.
Your calf muscles located at the back of your lower legs include two individual muscles. These are the gastrocnemius and the soleus.
One of the main functions of your calves is pushing the front parts of your feet down and stopping them from going up while you lean on them.
How hard your calf muscles have to work while using a stair climber depends on what step technique you have.
More specifically, if you keep your heels in the air, not on the steps, stair climber and stepper workouts will work your calves just a bit more.
Secondary muscles worked with stair climbers and steppers
There are also a variety of other muscles that have to work to keep you balanced and your body upright.
Some of the secondary muscles you work to do these things while using a stair climber include your hip abductors, hip adductors, and core muscles like your abs, obliques, and erector spinae.
Again, you can find where these muscles are and what they do in more detail below.
Hip abductors and adductors (outer and inner thighs)
Your hip abductors are the muscles in your outer thighs. Some of their names include the gluteus muscles (especially the minimus and medius), tensor fasciae latae, piriformis, and sartorius.
Hip abduction means moving your thighs sideways and outward. As you can expect, the muscles above make this happen.
On the inner side of your thighs, there are the hip adductors which include the adductor longus, adductor brevis, adductor magnus, gracilis, and pectineus.
Thigh adduction means moving your thighs to the center.
While using a stair climber, these outer and inner thigh muscles are mostly responsible for keeping you balanced. Especially, in the brief moments during each step where you lean on only one leg.
At the same time, these muscles will not have to exert the biggest amounts of force compared to what they are capable of.
Core muscles (waist)
“Core muscles” is a category name for the different muscles around your waist. The main ones are your abs (front), obliques (sides), and erector spinae (lower back).
These muscles work together to keep your upper body upright while standing up.
In turn, stair climbers and steppers work these core muscles to a small extent too. However, similar to activities like walking, not that much.
If you do tilt your upper body somewhat forward while using a stair climber, the core muscles in your lower back, as an example your erector spinae, will have to work a bit harder.
Does a stair climber build muscle?
If you want to grow and strengthen muscles, you have to pressure them with enough resistance and repetitions and give them enough rest.
Exactly what is enough depends on the current strength of the muscles you work with stair climber and stepper workouts.
A rough guideline is that if you are able to take more than 50 steps with each leg, you are likely not building much, if any muscle.
Since this will often be the case, it is fair to say that stair climbers typically do not build muscle.
Your leg muscles are relatively strong and already used to carrying around your body weight throughout the day. To grow them, you want to turn to resistance training exercises where you lift a lot of weight.
And even if you are able to build some muscle with stair climbers initially, this gym machine will likely stop being challenging enough relatively soon.
On the flip side, it is worth mentioning that just engaging your muscles without causing growth also offers benefits. This can improve endurance, make your muscles healthier, and slow down degradation.
Does the stair climber build abs?
For some reason, there is a common myth that stair climbers are great for engaging ab muscles.
Unfortunately, stair climbers will typically not build abs.
These muscles are responsible for moving your hips and chest closer to each other or at least preventing them from moving farther away from each other.
You will do this to a small extent while using a stair climber but generally not enough to see a lot of benefits.
Does the stair climber build glutes?
While stair climbers do work these muscles harder, this machine is typically not challenging enough to grow bigger glutes.
As briefly mentioned, your glutes are very strong muscles. Simply using a stair climber or stepper is typically not enough to challenge them to the point of muscle growth.
Instead, you want to do exercises like deadlifts, hip thrusts, and good mornings to grow and strengthen your glutes.
How to work your muscles harder with stair climbers
A benefit of stair climbers and steppers is that you can change up the workouts on them in a variety of ways. There are even a few things you can do to work your muscles harder.
First of all, some stair climbers and steppers allow you to adjust the step height. The higher you set this, the bigger the range of motion your muscles have to go through.
A bigger range of motion is generally beneficial for muscle growth and strength progress. You do still need to combine this with enough pressure.
To increase this pressure, you could consider wearing a weighted vest. Before doing this you do want to be able to check the weight limit of the stair climber or stepper you plan to use.
In some cases, there is also a resistance setting to make it so the steps give away less. This will again work your muscles slightly harder.