7 Muscle Groups You Activate When Running
Health & Wellness
You might be surprised to discover which muscles have been switched on during your run.
There's nothing like the feeling of finishing a run. Your body has worked hard and the surge of endorphins is giving you the famed runner's high. But which muscles specifically have been switched on throughout your run? Is it all lower body, as your feet strike out to carry you forwards? Or is it more upper body, with your arms driving you? Let's take a look.
Our Bodies Are Born to Run
Humans are the only primates who are bipedal. That is, we stand upright on two legs. Running is in our DNA. We evolved to run. In fact, due to how our bodies evolved, many scientists believe we're the best long-distance runners on the planet. Not necessarily sprinters—we can't outrun a cheetah. But the mechanics of our running stride, combined with our ability to thermoregulate through sweat, make us adapted to handle long distances.
So what are the biomechanics of our running stride that make us such effective runners? What muscle groups does running work? And how many muscles are used in running?
The Biomechanics of Running
As per the landmark study published in 1998 by Gait & Posture, there are two main phases of a runner's gait:
- Stance, or the time your foot is on the ground
- Swing, or the time your foot is in the air
This is known as the gait cycle. The stance phase is when your foot makes contact with the ground. As you lift your foot up from the ground and it travels forward, you enter the swing phase. Your body is aerial, or in float phase—both feet are off the ground. This cycle is repeated throughout the run, carrying you forwards.
Different muscles are activated during different phases of the swing cycle. To run faster or to improve your technique, it's helpful to understand which important muscles are involved in running.
What Muscles Are Used in Running
There are three key muscles that make up the hip flexors: the iliopsoas—psoas major and iliacus—and the rectus femoris. They are located at the front of the hip. In the stance phase, they are responsible for push-off as they flex and extend. They also control knee flexion and stabilise the spine and pelvis throughout the gait cycle.
Tight hip flexors are common but also vital to pay attention to. The tighter and shorter the hip flexor, the more range of motion is reduced and the shorter your stride becomes. This inhibits your natural gait and affects your form, which ultimately impacts running economy.
The gluteus maximus and gluteus medius play a key role in the stance phase. Strong glutes propel your body forwards, extending the hip as you bring your leg behind you. The glutes act as an anchor for your pelvis to stabilise movement, particularly during the float phase when both feet are off the ground.
Weak glutes negatively affect running economy and can increase injury risk. A study published in Clinical Biomechanics attributed knee pain to weak glutes amongst a group of runners. Another study that was conducted on runners with iliotibial band (IT band) syndrome had them complete a six-week glute-strengthening programme. After the trial, all but two of the runners were recovered. This gives a good insight into the power of the buttocks in running.
The quadriceps are a group of four muscles that comprise the frontal thigh muscle. If you've ever run uphill, you're bound to have felt a firing up of your quads. Undoubtedly, the quadriceps play a key role in a runner's stride. The quads bend the hip and extend the knee, stabilising and absorbing the impact as you land. This propels you forward, transferring energy to the hamstrings as you move from the stance to swing phase.
Located at the back of the thigh, the hamstrings are a two-joint muscle that extend the hip and control the leg. They are responsible for force production in the push-off phase. If you want to run faster or sprint efficiently, strong hamstrings are a necessity.
Many people, particularly women, are quad-dominant. That means that their quadriceps overcompensate. The ratio of strength and range of motion is outweighed from the quads to the hamstrings. This causes muscle imbalances that reduce running economy. Strengthening your hamstrings by weightlifting and other cross-training methods can help to improve your running performance.
Shin splints account for approximately 15 percent of all running injuries. This condition, known formally as medial tibial stress syndrome, is common amongst runners due to the activation of the calf muscles and shins during running.
The calf muscles play a huge role and have a variety of essential functions during running:
- The muscle that runs down the front of the shin, the tibialis anterior, moves like a rocker to lift the heels up off the ground during the swing phase. It shifts your body weight on your toes to propel you forwards.
- The soleus muscle in the calf flexes the ankle and stabilises and straightens the tibia, to keep your upright position.
- They are the first contact point, so they absorb the impact as your feet hit the ground.
- They spring your stride upwards and forwards as you transition through the gait cycle.
Weak calves fail to absorb the impact, which gives the appearance of a dragging, weighed-down stride. For a springy stride, strengthening your calves is essential.
Here are some calf-strengthening exercises to try:
- Skipping Rope: Jump on the balls of your feet over a rope. Make sure you land on your toes rather than on your heel. This will activate your calves. Try to build up to five minutes without stopping.
- Calf Raises: Stand on the edge of a step with your heels dangling off the edge. Use your calves to raise you upwards. Pause at the top, with toes spread wide and ankles flexed. Lower slowly to standing position. Repeat for 15 reps.
- Soleus Squat: With your back to a wall, walk your feet outwards and bend your knees. Lower into a squat, with your back and glutes making contact with the wall. Come up onto the balls of your feet. Perform an isometric hold for 30 seconds.
The muscles in your abdomen connect the upper and lower body together. While running, they are activated, keeping you upright and stable. Strong abs increase the stability of your lower body and generate force.
Sprinters will experience more abdominal activation. This is because greater hip extension takes place with each stride to generate speed. To prevent falling over, a slight spinal twist occurs to prevent excess displacement. The abdominal muscles—specifically the transverse abdominis and obliques—act as a foundation for the upper-body counter-rotation that keeps you stable.
Running predominantly works the muscles in your lower body. However, some upper-body strength is required for running. Your arms help drive you forwards, building momentum. Particularly the latissimus dorsi, shoulders and deltoids.
Having a strong back and shoulders can enhance your running economy. Not only will stronger arms provide more propelling power, having the upper-body strength to stay upright throughout your run can help prevent a hunched posture. Your posture during a run is a key part of running economy. A collapsed chest limits breathing capacity, which reduces the amount of oxygen and nutrients being delivered to your working muscles.