Running, like any physical activity, involves coordination among a group of muscles to propel you forward. So singling out one of those muscles as the “most important” risks oversimplifying the process. Yet certain muscles do play a more important role than others in running. And they may not be the ones that first pop into your mind.
In this article, I put forth three candidates for the most important running muscle designation. Although other muscles are also important, these three muscles deserve special attention partly because runners and triathletes living a modern lifestyle often fail to adequately strengthen and use them. This means they tend to be underutilized in relation to their importance. So here are the muscles, along with some exercises to increase strength and mobility.
1. The glutes: the primary engine of the posterior chain
Running engages a group of muscles known as the posterior chain. The prime driver of the posterior chain is the gluteus maximus, or your butt muscle. This muscle initiates hip extension, which is the essence of running. In addition to the gluteus maximus, the gluteus minimus and medius also get into the action with the medius playing an important role in stabilizing the hips during running.
Gluteus maximus for propulsion and power
The gluteus maximus is the largest and most powerful muscle in the human body, serving as the primary engine driving horizontal propulsion. During the stance phase of the running gait cycle, this muscle contracts forcefully to extend the hip, pulling the body forward over the planted foot. Developing strong glutes increases your explosive power output per stride, allowing you to sustain faster paces with lower cardiovascular demand.
Gluteus medius for pelvic stability
While the gluteus maximus provides forward power, the gluteus medius dictates single-leg lateral stability. Every time your foot strikes the ground, this critical stabilizing muscle contracts to keep your pelvis level and securely aligned. Without adequate strength in the gluteus medius, your hip structure undergoes micro-collapses with every step, wasting precious metabolic energy on lateral corrections rather than forward momentum.
Preventing pelvic drop and “runner’s knee” through glute strength
A weak gluteus medius contributes to pelvic drop, in which the hip opposite the weight-bearing leg dips downward during the stance phase. This instability forces the knee of the supporting leg to collapse inward, placing severe stress on the patellofemoral joint. Strengthening the glutes helps improve your stance, reducing the risk of common overuse injuries like iliotibial (IT) band syndrome and “runner’s knee.”
Many runners and triathletes suffer from weak or inactive glutes due, in part, from the modern lifestyle that involves substantial amounts of sitting. All that time sitting at a desk or in a car puts your glutes to sleep. This “sleepy glute” syndrome negatively impacts your running and cycling because the prime muscles that drive the posterior chain go missing in action.
The donkey kicks exercise strengthens and activates your glutes. Get on your hands and knees. Keep your back straight, flat and still. Squeeze the glute to move one leg back and slightly to the side (like a donkey kicking). Note: the movement should be initiated from the glute (butt), not the lower back. If you feel the lower back working instead, start with smaller movements until you can increase the range of extension. Do 2-3 sets of 8-12 repetitions.
2. The deep abdominals: the foundation of core integrity
Effective running requires excellent posture, and a prime muscle responsible for maintaining good posture is the transversus abdominus (TVA), or your deep abdominals. This muscle wraps around and stabilizes your core much like a corset or girdle. It lies below the more famous abdominal muscle, the rectus abdominus, responsible for the “six pack” look.
As with the glutes, if you sit a lot, the deep abdominals can become weak and underutilized.
The role of the transverse abdominis in running posture
The deep abdominals provide stability so that the posterior chain muscles can work more effectively, preventing the forces generated by the posterior chain from reverberating through your joints and spine. Actively conditioning the TVA provides a solid, rigid foundation that maintains an efficient, upright running posture across varying terrains.
Connecting core strength to efficient stride mechanics
Your core transfers kinetic force between your upper and lower body. A stable TVA minimizes unnecessary torso rotation, ensuring that the counter-balancing forces of your arm drive are smoothly translated into forward leg turnover. This structural integration maximizes your overall running economy.
Preventing postural collapse during endurance efforts
As glycogen depletion sets in during long, muscular fatigue causes athletes to slouch or lean forward excessively from the waist, which constricts the diaphragm and reduces lung capacity. Maintaining deep abdominal strength prevents this postural collapse, preserving optimal respiratory volume and structural efficiency deep into a race.
Use the plank pose to strengthen and activate your deep abdominals. Lie in a prone position (face down) with your elbows under your shoulders. Squeeze the quads and then squeeze the glutes to raise your body into a plank. Keep the back flat, and do not let the butt rise or sink. Hold for 30 seconds or up to three minutes.
3. The big toe: the secret to explosive propulsion
Although far removed from your core, your big toe nevertheless plays an important role in running. The flexor hallucis brevis, or big toe muscle, bends the big toe and works to stabilize your foot during each foot plant.
Modern running shoes are notorious for design features that prevent your big toe from working the way it should while running. Shoes with a narrow and elevated toe box place the big toe in a hyperextended position and prevent the toes from spreading while running, a recipe for a series of imbalances that can lead to common running injuries from shin splints to plantar fasciosis.
Understanding the windlass mechanism and foot intrinsic muscles
The hallux, or big toe, plays an extraordinary role in running biomechanics through a process known as the windlass mechanism. When your foot preps to push off the ground and the big toe extends upward, it pulls the thick plantar fascia tightly around the first metatarsal head. This mechanical pulling action shortens the distance between your heel and toe, lifting your medial arch and transforming a flexible, shock-absorbing foot into a rigid, highly efficient lever for propulsion.
Why big toe strength dictates stride power and stability
If your foot intrinsic muscles and great toe lack sufficient structural strength, your foot will collapse into excessive pronation during the terminal stance phase. This forces the ankle to roll inward, leaking precious kinetic energy and destabilizing your entire lower limb alignment. Robust big toe strength ensures a stable, anchored platform, allowing your foot to fully utilize the elastic rebound forces of your Achilles tendon.
Strengthening the great toe for better toe-off mechanics
Exercises like “toe curls” (using your toes to scrunch a towel on the floor) and “short foot” protocols actively recruit the abductor hallucis and foot intrinsic networks. Strengthening these pathways ensures that when your foot leaves the ground, power transfers cleanly through the first metatarsal, maximizing forward horizontal velocity.
In addition, work to increase the flexibility, coordination and strength of your big toe by doing what physical therapist Jay Dicharry terms “toe yoga.” While barefoot (either standing or sitting), keep your feet flat on the ground. Raise your big toe while keeping the other four toes on the ground. Return your big toe to the ground; then raise your other four toes. Repeat this several times throughout the day to put your big toe back into the action.
Choose shoes that fit your feet (rather than trying to cram your feet into narrow shoes) and allow your toes to splay naturally while running. Toe spacers such as Correct Toes, a product designed by Portland podiatrist and runner Ray McClanahan, work well to align and strengthen your toes.
From your core to your toes
Singling out any one muscle as the most important running muscle risks overlooking the intricate coordination involved in the activity, but there are certainly some candidates that deserve special attention. To run efficiently and injury free, be sure to focus on improving the strength and mobility of the muscles discussed here. Even a little bit of supplemental work goes a long way and pays valuable dividends, so there’s no excuse not to fit these or similar exercises into your busy schedule.
FAQs
There is no single most important muscle. The gluteus maximus is a contender because it serves as the primary engine of the posterior chain and generates the explosive hip extension and horizontal propulsive force needed to drive you forward. But running power doesn’t come down to one muscle—it involves coordination of many muscles.
Yes, running heavily engages your gluteal muscles. While standard jogging offers a baseline stimulus, adding steep hill repeats, bounding, and speedwork targets fast-twitch fibers for significant power and muscle toning.
When deep abdominal fatigue sets in, runners begin slouching or bending forward from the waist. This postural collapse physically constricts the diaphragm, which reduces total breathing volume and running economy.
References
Bolgla, L. et. al. (2004, Jan-Mar). Plantar Fasciitis and the Windlass Mechanism: A Biomechanical Link to Clinical Practice. Retrieved from: https://pmc.ncbi.nlm.nih.gov/articles/PMC385265/
Buckthorpe, M. et. al. (2019, Jul 14). ASSESSING AND TREATING GLUTEUS MAXIMUS WEAKNESS – A CLINICAL COMMENTARY. Retrieved from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6670060/
Whiler, L. et. al. (2017). Gluteus Medius and Minimus Muscle Structure, Strength, and Function in Healthy Adults: Brief Report. Retrieved from: https://docs.google.com/document/d/1qXYrRykGjZrpmdJ1YE-DK_nrp__nsOEimZgROn7zd9Q/edit?tab=t.j0v7i4prdhqq
Yang, H. et. al. (2026, Jan 5). Short foot exercises for flatfoot therapy: Status and prospects. Retrieved from: https://pmc.ncbi.nlm.nih.gov/articles/PMC12775274/
