When you move, you engage different muscles. That means pedal exercisers work a few muscles too. Find out which ones.
The main muscles you work with pedal exercisers include your quadriceps (front thigh muscles) and to some extent your hamstrings (back thigh muscles), calves, and foot extensors (shin muscles that raise your toes).
Since your quadriceps are relatively strong, using a pedal exerciser will typically not be enough to grow these muscles.
You can also use pedal exercisers with your arms. This will work your deltoids (main shoulder muscle), triceps (back upper arm), pectoralis (chest muscles), biceps (front upper arm), latissimus dorsi (middle/upper back), and trapezius (upper back).
Some of these muscles are relatively weak so there is a chance you can grow some of them a small amount with pedal exercisers.
That being said, you should still see this device as a cardiovascular strengthening tool. Not something to build muscle (at least not effectively).
Pedal exerciser muscles worked
To rotate the pedals of the device there will be a few muscles that have to exert force. Even though pedal exercisers are typically cardiovascular workouts, it can be worth finding out what muscles you will use.
Muscles worked using a pedal exerciser with your legs
When using pedal exercisers with your legs, the main muscles you work are your quadriceps (front thighs) and to some extent your hamstrings (back thighs).
The quadriceps are the muscles in your front thighs that extend aka stretch your legs at the knees. These will be the main muscles responsible for pushing down the pedals.
On the other side of your thighs, there are the hamstrings. One of their functions is flexing/folding your legs at the knees.
This movement will typically offer less of the force that moves your body because you are not really pulling the pedals of the exercise back that much.
At the same time, they are still worth mentioning because they put your legs in a position where the quadriceps can exert force again.
Lastly, pedal exercisers work your calves and foot extensors (shin muscles that raise your toes) to a small extent too.
Your calf muscles help you push down the front parts of your feet and prevent them from going up. The more forward the pedals rest against your feet, the more your calf muscles will have to work.
If you want to get really detailed, you can find out what parts of the calf muscles you engage more.
In a seated position, the soleus calf muscles (lower and deeper calf muscles) have to work the hardest and the gastrocnemius calf muscles (the upper calves) somewhat less.
Next, foot extensor muscles like the extensor hallucis longus and the extensor digitorum longus along your front shins raise the front parts of your feet.
Muscles worked using a pedal exerciser with your arms
When using the pedal exerciser with your arms, your deltoids (main shoulder muscle), triceps (back upper arm), and pectoralis (chest muscles) will push the pedal away from you.
Your latissimus dorsi (middle/upper back), trapezius (upper back), and bicep (front upper arm) muscles are responsible for pulling the pedal toward you.
Do pedal exercisers build muscle?
If you want to build certain muscles, you have to pressure them with enough resistance and repetitions. What is enough depends on your current strength.
That being said, a rough guideline is that if you can complete more than 50 rotations with each leg (or arm) you will likely not grow any muscles.
This will often be the case since the leg muscles you work are relatively strong. In turn, you can say that pedal exercisers will typically not build muscle.
If you use this device with your arms, it is just a bit more likely that you could see muscle growth.
However, even then, pedal exerciser workouts are typically good for improving cardiovascular health, not building muscle.
It is worth noting that you do not have to build muscle to see benefits in this area. Just engaging your muscles can help prevent degradation, improve endurance, and make the muscles healthier.
How to work your muscles harder with pedal exercisers
So while you likely still won’t build muscle, you can get some of the benefits of engaging your muscles to a larger extent by making your pedal exercise sessions harder.
A benefit of pedal exercisers is that they typically have a way to adjust the resistance. In simpler words, how hard it is to push the pedals.
By increasing the resistance of your pedal exerciser, the muscles you use will have to work harder. This can lead to slightly more benefits.
In theory, you could also wear ankle weights to make the horizontal part of the movements slightly harder. That being said, the previous method will generally be more effective.