The Most Important Muscles Used When Running

Looking to learn more about the most important muscles used when running?

Then you are in the right place.

Muscle Anatomy – An Introduction

The human body is an amazing piece of “machinery,” and muscles are a big part of what drives it.

In fact, there are roughly 650 to 850 muscles. The exact number depends on whom you are asking, and  how you count them since most experts have different opinions of what constitutes a distinct muscle.

But that’s not going to be a problem for us today. As long as you’re willing to take good care of your muscles, you’re good to go.

Some of our muscles primary functions include moving our body parts, keeping us upright, maintaining posture, generating heat, and operating certain bodily functions, such as digestion and blood pressure.

But when it comes to running, muscles are especially useful.

For that reason, in today’s post, I’m delving a little deeper into the main muscles used when running.

Why Should You Care

Having a basic knowledge of the muscle groups used the most while running is essential, especially when it comes to strength training and injury prevention.

So, are you excited?

Then here we go.

The Main Muscles

Every muscle plays a role in locomotion.

Nevertheless, some are more important than others when it comes to running.

Also known as movers, these are the muscles engaged the most when running, and are chiefly located in the legs and hips.

That said, before I get into the main muscles, let’s first take a quick look at muscle tissue types.

The Main Muscle Types

There are three distinct types: cardiac, smooth, and skeletal. Each type serves a specific role in the body, with a particular structure and a definite function.

The Cardiac Muscles

Cardiac muscles are solely found in the walls of the heart. They, in essence, contract the heart to pump blood.

Cardiac muscles are striated—meaning that the muscle fibers contain alternating light and dark bands known as striations.

This type muscle fiber is under the control of the autonomic nervous system — meaning that its contractions are NOT under conscious control.

That said, even in the absence of nervous input, contractions can still occur due to cells known as pacemaker cells.

These muscles are also highly resistant to fatigue thanks to the high concentration of mitochondria, myoglobin, and a decent blood supply allowing for constant aerobic metabolism.

Smooth Muscles

Smooth muscles are found in the walls of hollow internal structures, such as the stomach, urinary bladder, bronchi, esophagus, and in the walls of blood vessels.

In other words, these are the muscles of the organs.

Smooth muscles change shape to facilitate bodily functions, such as blood pressure, digestion, breathing, raising hairs, focusing eye, etc.

The second type of muscle tissue is usually involuntary—under no conscious control.

Further, its tissue is unstriated, meaning it does not have the stripy appearance of cardiac and skeletal muscles.

Skeletal muscles

Last but not least, you also have skeletal muscles (the topic of today’s post).

Skeletal muscles are made of very elastic fibers connected by tissue and named for their location—attached to the bones.

The human body contains more than 640 skeletal muscles, accounting for about one-third of the human body mass.

For that reason, these are the primary muscle type in the human anatomy.

Skeletal muscles have the primary function of moving of our bones and other structures.

In fact, these are used to create movement in any form of physical activity, including running.

Skeletal muscles can be made to contract or relax through conscious control using nervous impulses from the brains sending messages to the muscles.

Thus, unlike the other two types, these can be considered voluntary as it’s possible to have conscious control over them.

The third type include key running muscles such as the quadriceps and glutes, as well as muscle beach favorites, like triceps, biceps, pecs, abs, etc.

The Most Important Muscles Used When Running

The main running muscles include the quadriceps, hamstrings, glutes, hip flexors and calf muscles.

With that in mind, your body also relies on secondary, or assistant, muscles to keep you going forward.

These include the abdominal and the upper body muscles—all of which help provide stability throughout the gait cycle and improver overall speed and running economy.

The main muscle groups consist of:

The Quadriceps

As you move your leg forward, you’re primarily using the quadriceps muscles, the muscles located on the front of the thighs.

The quads run from the hips and upper femur down to the patella—the kneecap. They  consist of a group of four muscles that include:

  • The Vastus Medialis,
  • Intermedius,
  • Lateralus, and
  • Rectus Femoris. See picture.

All of these four muscles work hand in hand to bend and extend your knee when walking, running, or whenever doing any type of knee bending motion.


In essence, your quads help in:

  • Extending the knee. They are, in fact, the primary muscles called upon in the “drive” phase.
  • Bending your hips. Your rectus femoris (see picture) is responsible for flexing the hips—the motion necessary to lift your feet off the ground.
  • Lifting the knee towards the chest—critical for increasing stride length and sprinting speed.
  • Straightening and stabilizing your knees during running stride as the four heads of the quad are connected to the patella—the kneecap.
  • Absorbing the shock of impact upon landing, then dispersing it as it passes through the rest of the body.

Downsides of Weakness

A common dysfunction among many runners is that they are disproportionately strong and tight through their quadriceps compared to their hamstrings.

Such dysfunction can have an adverse impact on leg posture and proper positioning, increasing the risks of overuse injury in the lower back, pelvis, hips, and the knees.

So, to err on the side of caution, keep strengthening your quadriceps as well as stretching them.


Some of the best quad strengthening exercises include leg extensions, leg lifts, lunges, and, squats.

The Hamstrings

As your body moves forward, the action switches from the quads to the hamstrings.

The hamstrings are, basically, the single large tendon found behind the knee. The hamstrings span two joints—the hips and knee, and are made up of four muscle-parts.

As pictured, these consist of:

  • The biceps femoris, (two parts: long head and short head).
  • The Semitendinosus, and
  • The Semimembranosus

These muscles are involved in many of our daily activities, including walking, jumping, running, etc.


The hamstrings play a key role during different phases of running gait, but most notably, they are essential for:

  • Initiating knee bending as your body moves forward
  • Flexing your knees, causing your feet to move back toward your butt. This helps provide power to propel you forward.
  • Assisting the extension of thighs by moving the upper leg backward.

Downsides of Weakness

More than often, runners are notoriously known for having tight hamstrings that are weak in comparison to the quadriceps, their opposing muscle group.

Further, chronic hamstring inflexibility is also widespread in runners who have desk jobs and/or spend a lot of time sitting.

Such dysfunction can affect the efficiency of the kinetic chain at the hip and knee, increasing the risks of pain and injury.

More specifically, limited hamstrings function increases the risks of:

(1) Hamstring tears, which is caused by the muscle’s inability to withstand the load generated by the contracting quad.

(2) Hindered running performance due to the diminished power from the knee extensors and hip flexors.


Good exercises includes deadlifts, lying leg curls, hamstring pushups, and dynamic stretches (think yoga).

The Gluteal

The gluteals consist of a group of three muscles which make up the butt: The Gluteus Maximus, medius, and minimus and are located in the buttocks.

The Gluteus Maximus, the muscle responsible for creating the shape of the buttocks,   is the largest and strongest of three.

This muscle is also in charge of hip extension and plays a vital role in spinal and pelvic stabilization.

When it comes to running, these are the main source of power.

So, if you are serious about getting the maximum bang for your buck, adding strength and power to these muscles is the first step to take.


Your glutes have a number of roles in providing stability, power, and strength in the pelvis and hip region in three planes of motion. Especially for:

  • Stabilizing your hips and legs.
  • Extending the hip, then straightening it beneath you. In fact, hip extension is a motion that primarily involves the glutes.
  • Keeping your posture straight, and the trunk stable and upright.
  • Maintaining proper knee alignment while running.

Downsides of Weakness

Even if you’re a committed runner and strength train regularly, chances are you spend the bulk of the remainder of the day sitting down, especially if you have a desk job.

Because of our “sitting lifestyle,” our glutes are have become neutrally inhibited.

Why is this bad?

Sitting for prolonged periods of time can tighten and weaken the glutes, causing bad posture and hindering running ability.

This also leads to excess stress on the lower back, knee pain, and other serious trouble.

For example, research of Div. III collegiate athlete revealed that subjects who reported suffering from “patellofemoral pain”—technical name for knee pain—had drastically weaker hip abductor and external rotator muscle of the affected limb.

Check these links for more on the subject.


Good exercises include squats, sumo squats, walking lunges, clamshells, glute bridges, etc.

Hip Flexors

The hip flexors are the muscles located on the front of the hip, just above the thighs.

Also known as the iliopsoas, every time you lift your leg, whether when walking, running, or doing any sort of leg lifting motion, the hip flexors are called up into action.

The hip flexors are made of two muscles: the iliacus and the psoas major.

The psoas major is the largest of the muscles, stretching from the  T-12 spinal vertebrae to the L5 spinal vertebrae and there it attaches to the femur—your thigh bone. See picture.

Since these muscles lie deeper than quadriceps and hamstrings, they’re often neglected in strength training.


The hips are key for:

  • Moving your legs forward and back while working in conjunction with the hamstrings and quads.
  • Stabilizing the hip joint.
  • Developing good running posture and form.
  • Maintaining a standing position (in conjunction with the muscles of the lower leg, core, neck, and shoulders).
  • Stabilizing the pelvic region while keeping the hips level.

Downsides of Weakness

Study shows that many overuse injuries can be traced back to dysfunction/weakness in this important muscle group.

For example, a growing number of studies have linked weak hips and runner’s knee. In fact, a study revealed that women with a history of runners knee had greater hip instability in their gait.

Another research conducted at the Standford University found that runners who are prone to knee pain had a relatively weaker hip strength when compared to injury-free runners.

The good news is, most of the injured runners were able to return to training following a six-week hip strengthening training program, the researchers concluded.

Furthermore, weak iliopsoas are often blamed for severe hip pain.

So, if you have a history of hip pain, on or off the running track, consider strengthening or stretching these muscles more frequently, or see a certified physician or a chiropractic specialist for more.

Resume running once it’s pain-free.


Some of the ideal hip strengthening and stretching exercises include weighted hip extensions, bridges, runners lunges, pendulums, skaters squats, pigeon, and seated butterfly stretch.

The Calves

The calves are the muscles located on the back of the lower leg, below your knees.

They consist of:

  • The large gastrocnemius (outer calf), forging the clear bulge beneath the skin and
  • The smaller soleus (inner calf), which is the flat muscle lying underneath the gastrocnemius muscle.

The two calf muscles attach to the heel via the Achilles Tendon, which inserts into the calcaneus, the heel bone.


The calves are essential for:

  • Providing spring in your step as they help in pushing off the ground to move forward.
  • Extending and flexing each foot as you land and push off.
  • Providing movement around the ankle joint and the phalanges. In fact, the calves are called upon during all forms of motion, including running.
  • Maintaining balance and ankle flexion.
  • Reducing shock impact. They absorb much of the impact every time you take a step when running.

Downsides of Weakness

According to conventional wisdom, calves weakness/dysfunction is believed to be one the leading cause of a host of injuries, including calf strains, shin splints, Achilles tendinitis, plantar fasciitis, and even hip or hamstring issues.

For instance, weak calves can place excessive strain on the Achilles and damage the fibers that make up the tendon. This always leads to pain.


Good exercises include calf raises, step lunges, etc.

Supporting Muscles

Along with the primary muscles, several other muscle groups are important in running, therefore, are an integral part of any well-rounded strength training program.

Assistant muscles are critical for keeping good form while running, which can help ward off discomfort/injury and make your runs more efficient.

The assistant muscles include the muscles of your core and the upper body.

The Core Muscles

Most of the core muscles, including the abs, paraspinal, pelvic floor, obliques, erector spinae, multifidus, diaphragm, and hip girdle muscle, are vital for a runner’s form, the efficiency of movement.

Although, as a runner, the muscles of the legs are the source of power, your core muscles are the critical foundation from which all movement, including foot strike, stems.

You can have the strongest legs in the universe, but without a strong core, you won’t be able to engage your legs’ strength efficiently.

Furthermore, strength and stability in the core region can also protect your spine and lower back from the impact of running. And that’s a good thing if you ask me.

The Functions

The core plays a major role in providing the following while running:

  • Running efficiently since they’re essential for maintaining balance and controlling joint movement.
  • Improve your running efficiency by improving the energy transfer between your upper and lower body, helping your body work as one single unit.
  • Keep you standing upright and avoiding an excessive forward lean that can put undue pressure on your lower back.
  • Supporting your upper body and hip movements during running.

Downsides of Weakness

With a weak core, you’ll be unable to reap the above benefits, which can drastically hinder your running performance, and might even increase the risks of injury. And you don’t want that.

Upper Body Muscles

Though they are not heavily relied upon, several muscle groups in the upper body are relied upon while running.

The most important ones include the muscles of the arms, chest, back, and shoulders.

Other muscles, such as the rotator cuff, the trapezius, the erector spinae, and the latissimus dorsa, are not as important as the beforementioned.

The functions

Here are the main functions of each of your upper body muscles:


Your arms are in charge of maintaining a rhythmic motion that’s in tune with lower body—key for efficient running—so strengthening them can improve form efficiency.

To get more of the arm swing, bend your arms at the elbows and swing them back and forth during the running gait cycle.


Your biceps branchii, better known as the biceps, is key for maintaining a bent arm.

Also, strong biceps help you swing your arms back and forth with more power.


These are located above the elbows and allow you to flex your elbows and rotate your forearms, which help swing them back and forth to enhance balance and forward propulsion.

The back

Your back muscles work to maintain proper posture.


Some of the best upper body exercises for runners include pushups, hammer curls, bicep curls, shoulder presses, pull-ups, kettlebell swings, and resistance band exercises.

Note: Sure, a bulky, heavy, upper body will only slow you down.

That said, as a runner, you don’t need the upper body of professional strongman or bodybuilder to get the benefits.

Contrary to popular thinking, all you need to reap all the reward of strength training is to just do two to three 20 to 30 minutes strength session per week. Of course, feel free to do more, if that’s what you want.

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That’s it. The above is all you need to know about the muscles used when running. Just make sure to heed the advice and do take good care of your running muscles. Otherwise, you’ll be in big trouble. And you don’t want that.