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What Muscles Does Running on A Treadmill Work?

muscular calves on a treadmill

Running is a great way to get in shape, but did you know that there are two different types of running? Outdoor running and treadmill running. When comparing the two, it’s important to look at which muscle each variant works. It’s common to wonder what muscles does running on a treadmill work and is it different than running outdoors?

Running on a treadmill works the hamstrings, quadriceps, calves, glutes, abdominals, spinae erector muscles in the back, and the heart. While all of these muscles are important, the heart, and subsequent cardiovascular benefits, may be the most critical.

While both have their own set of benefits, indoor running can be more beneficial for people who are just starting or when certain conditions limit their ability to run outdoors. Things like cold weather, allergies, safety concerns, insecurity about your form or weight, and various other factors can influence our ability to run outdoors.

In this article, we’ll take a closer look at the differences between outdoor and indoor running, and why indoor running might be a better option for some people. Let’s start off with an overview of the muscles worked on a treadmill and running outdoors.

What Muscles Does Running on A Treadmill Work?

There are 5 main muscle groups worked by running in general. Treadmill running and running outside work them similarly, but we’ll dive into some differences due to things like incline and other factors. Other explosive exercise movements, like jumping, are also affected by the types and distance of running done.

The five main muscle groups are:

  • Hamstrings
  • Quadriceps
  • Glutes
  • Calves
  • Heart


The hamstrings are a muscle group made up of three muscles that extend from the pelvis to the back of the knee. The hamstrings are important for running because they help to flex the knee and extend the hip.

One potential disadvantage of running on a treadmill is the lack of hamstring engagement. While it is still clearly used, it may be used less than it is when running outside due to the lack of incline (assuming you don’t use the incline).

Outdoors, inclines and declines are almost a constant as very little natural ground is perfectly flat. Indoors, you are running at 0% almost exclusively.


The quadriceps muscles are a muscle group made up of four muscles that extend from the pelvis to the kneecap. The quadriceps help to straighten the leg and also assist in activities such as walking and climbing stairs. We’ll touch on incline later on in the article, but here’s a spoiler: adding incline can really get a fire burning in these babies.

Interesting read: The difference between runners’ legs and cyclists’ legs. A large part of the difference is the development of the quadriceps muscle.


The glutes are a muscle group made up of three muscles that extend from the pelvis to the top of the thigh. The glutes are important for running because they help to stabilize the hip and provide power during the running stride.


The calves are a muscle group made up of two muscles that extend from the back of the knee to the Achilles tendon. The calves are important for running because they help to flex the foot and provide power during the running stride.


The heart is a muscle that pumps blood throughout the body. Running, and any other type of exercise, help to strengthen the heart muscle and improve cardiovascular health.

Now that we know which muscles are worked by running in general, let’s take a look at how treadmill running and outdoor running differ.

Can You Get Toned by Running on A Treadmill?

Running on a treadmill burns calories and helps build muscle which, after consistent effort over some time, will tone your body.

We all know that running is a great way to lose fat, build muscle, and get the toned physique we all want. But, can you get as toned by running on a treadmill just like you do running outside?

The actual body mechanics of running on a treadmill vs outside are very similar. There are some differences, however, so be cognizant of that when switching. One common issue is ankle pain due to the different foot strike from a treadmill to the street.

One myth is that running on a treadmill is bad for your knees – research shows this is not the case.

What Parts of Your Body Does a Treadmill Tone?

When you lose the subcutaneous layer of fat and expose the underlying muscle, your body looks toned. Treadmills can tone any part of the body via fat loss, however, the majority of the muscle-building benefits come from the waste down.

While the majority of muscle-building benefits come from the legs and butt, you can build muscle all over your body by running on a treadmill. It can have an impact on overall appearance and make you look much more muscular in general.

Adding incline to your treadmill workout will help to build more muscle as it recruits more muscle groups.

Interval training is also a great way to build muscle when running on a treadmill. Interval training is when you alternate between periods of high intensity and low

Does a Treadmill Tone Your Stomach?

Running on a treadmill can in fact tone your stomach. It will help you to lose the layer of fat that covers your stomach muscles, giving you a toned appearance.

To tone your stomach more, adding some core exercises to your routine is a great idea. The muscles in your core are very important when running.

“Improper function of this musculature may lead to abnormal spinal loading, muscle strain, or injury to spinal structures, all of which have been associated with increased low back pain (LBP) risk.”

Source: Journal of Biomechanics
runners on a treadmill

Engaging your core muscles while running will help develop them. Coupled with the fat loss from excess calorie burn, assuming your nutrition is on-point, will definitely assist in toning your stomach.

Is Treadmill Good for Toning Thighs?

Treadmills help tone thighs by activating the quadricep muscles to assist in straightening the leg with each step you take running. If an incline is added, or something like running stairs, the quadriceps get even more of a workout.

Again, fat loss through exercise and building the quadriceps muscles from an incline running exercise plan will get those thighs toned up and looking great.

Does Walking on Treadmill Build Glutes?

Treadmills help build glute muscles by requiring you to use them with each step while walking or running. The more incline, the more the glutes have to work.

“Treadmill walking is an effective way to tone the buttocks and thighs.”

Source: Livestrong

In a 2012 study by Clinical Biomechanics, it was shown that women use their glutes 40% more than their male counterparts when running. Since a well-developed glute area is desirable for women, this is great news!

Men, don’t lose heart. Running is a great glute developer for you as well. In fact, running on a treadmill or outdoors will do wonders for your entire lower body from the hip abductors on down.

So, there you have it. Treadmills are a great way to tone your whole body, not just your legs like many people think.

Be sure to add some incline and maybe some intervals for the best results

What Muscles Does Running Uphill Work

man running uphill

Running uphill utilizes more muscles than running on a flat surface. When running uphill, your calves, hamstrings, glutes, and quads all have to work harder.

Your stabilizer muscles also have to work harder as your body tries to maintain balance while going up an incline. This helps to improve your overall stability and coordination.

Running uphill is a great way to tone your lower body and improve your cardiovascular fitness at the same time. It is also less impactful on your joints than running on a flat surface, which is beneficial for people who are prone to injuries.

So, if you’re looking for a workout that will tone your legs and improve your cardio without putting too much strain on your body, then running uphill is a great option.


To sum it up, running on a treadmill is a great way to work the primary muscles in your legs and hips as well as some abdominal and upper body muscle-building benefits.

Not to be forgotten about, one of the most important muscles we have is the heart. Running is a great cardiovascular workout and improves heart health with every mile you pound down the road.

If you’re looking for a workout that will improve your cardiovascular fitness and tone your lower body, then running on a treadmill is a great option. If someone asks you what muscles running on a treadmill work you should be an expert. Use this knowledge at the local gym, track, or simply around your neighborhood. Whatever you do, get out and run!

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About the author

Jasper loves to write about fitness, running, and anything else that gets him moving outdoors. He's an avid hiker, backpacker, and climber who loves to stay fit so he can make sure he's healthy enough to enjoy his favorite hobbies. He also spends time writing about his true passions in life.