What Muscles Does a Treadmill Work?

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Treadmills are excellent cardio machines, but they aren’t just getting that heart rate up. Beyond getting that blood pumping, you also work out various muscle groups.

Is this going to work like a rowing machine or a smith machine? Of course not, but it’s a bit more motivation to hop on the treadmill, strengthen the rest of your body, and prove that cardio is not a waste of time (inside the gym, or out).

There are five main muscles that you work out. Let’s talk about them.

#1 Quadriceps

What Muscles Does a Treadmill Work

Your quadriceps, most commonly just called quads, are basically the main muscles in your thighs. When you hear about leg day, this is the muscle you’re supposed to be working out.

Quads are vital to everything you do. They help bring pressure and stress off of your knees, they keep you balanced, and they have to be worked out to really access your glutes if you’re trying to exercise those as well.

When you feel a burning in your leg after running on a treadmill all day, it’s most likely going to be in your quadriceps.

These muscles produce a ton of lactic acid, which is normal, but it means that you might need a bit more recovery time for your quads to recoup after an intense exercise.

If you’re hopping on a treadmill anytime soon, this is the most important muscle to know about, but now the only one. Let’s talk about some muscles that you might not expect, and how your treadmill exercise helps.

#2 Back Muscles

#2 Back Muscles

Your back muscles get a wee bit of a workout, and it’s all connected to your forearms, which we’ll talk about later. Unless you’re a robot, you’re not going to keep your arms perfectly stable by your side when you walk or run on a treadmill.

You’re pre-built to use those arms to help with momentum shifts while you walk. It’s why we swing our arms even when we’re just going to the store, or doing another activity outside of exercise.

As your arms come back, they work your back muscles. It’s only very slight, but it does help with muscle building. You’ll also notice that when you’re running, you keep your back straight, which also helps put some of that pressure on your back, in a good way.

#3 Hamstrings

What Muscles Does a Treadmill Work

Hamstrings are the dark underground of your quadriceps. These are in the thigh, but they run along the back of your thigh from just below your knee, all the way up to your hip. In fact, your hamstrings are longer than your quads.

It takes longer than most people think to work out your hamstrings. It can be a difficult task, but the payoff is beyond worth it. Your hamstrings help with stretching, movement, stability, and so much more.

However, it’s also the Achilles heel of your thigh. If you’ve ever heard of someone pulling a hamstring, that’s because muscle tears are more common here than anywhere else on your leg.

These tears are painful because your hamstrings stretch below your knees, so you feel bouts of pain every time you stretch or stand up. It’s not a nice feeling.

A genuinely pulled hamstring (not just a little muscle soreness) can sometimes be seen through your skin. The entire area gets red and inflamed.

The point of this precautionary tale is to say this: your hamstrings are important, and you should treat them that way. Your treadmill is the best way to exercise your hamstrings.

#4 Pectoral Muscles

What Muscles Does a Treadmill Work

Similar to how the back works, your pectoral muscles are also moved when your arms sway. Some athletes will use hand weights while they’re on the treadmill to give extra resistance. This works out the back and the pectoral muscles fairly well.

You’re not going to see major pec gains just from using the treadmill, but you will see reduced fat, you will keep fat off, and there is some muscle growth that happens. It’s just limited.

You can add free weights to your treadmill routine, as long as you aren’t running or moving too fast. Consider doing curls while walking on the treadmill to boost back and pectoral muscle growth.

As you might imagine, the more arm movement you have while on the treadmill, the more you’ll work these muscles out. High-intensity treadmill cardio does more for additional muscles, like the pecs, than brisk walks will do.

#5 Forearms

#5 Forearms

Your forearms don’t get beefy on a treadmill, but they do get a workout. You don’t make gains in the usual way that people would think. It’s not just from arm momentum; you have to hold them tight as if you were doing a core exercise.

This increases resistance when your arms sway up and down, but it also just engages your muscles in a better, more optimized way than loose swings will.

Forearms will also benefit from added free weights. One excellent way to work out your forearms is by holding onto the railing and gripping firmly while you run. Your shoulders will sway side to side, and the firm position your hands have will stretch your forearm muscles.

A treadmill is a cardio machine first. You won’t get incredible results, but if total weight loss is something you’re striving for, keeping off any extra fat from your forearms that you can is a bonus.

Not Exactly a Full-Body Workout

It may not be a full body workout, but a little bit on the legs, arms, and even your chest is nothing to scoff at. Every day and every single bit of effort you put into your exercise helps.

Treadmills are all about intensity, so don’t let yourself get complacent with putting this thing on a two and casually walking. Boost the intensity, reap the rewards, and see the difference in the mirror.