You Gotta’ Have Guts: The Role of Visceral Mobility in Running

How visceral mobility is needed for healthy endurance running.

By on March 10, 2020 | Comments

Stay the CourseDo you have guts? As endurance runners, of course you do, am I right? But do your guts move?

(If you think this column is getting weird, we’re just getting started!)

‘Visceral’ (abdominal organ and tissue) mobility is real thing. Our innards need to move, and that motion is important for both optimal function and fast, efficient running.

Paradigm-Breaking: What are Viscera and Why Those Organs Need to Move

The Western sports-medicine paradigm for injury tends to center around three tissue types: muscle, tendon/ligament, and bone. When a runner has pain, s/he tends to think of one of three things:

  • Is it a sprained/strained muscle?
  • Is it tendonitis?
  • Is it a broken bone?

Over the course of eight years of writing “Stay the Course,” I’ve attempted to expand horizons, highlighting other possible sources of pain and dysfunction. Chief among important pain-generating tissues are the nerves (signs and symptoms, identification and treatment) and the role of the brain (here and here).

Fascia as another key tissue. The thin, ubiquitous-yet-enigmatic connective tissue that surrounds muscle bundles (a la the casing around a sausage) also surrounds and connects all tissues in the body. Fascial mobility is crucial for optimal running mobility throughout the body.

Fascia also covers our viscera, the term referring to the collection of internal organs and tissues housed in the space within our ribcage, abdomen, and pelvis. The visceral organs are our body’s true engine. They digest food to create propulsive energy, excrete wastes, and perform myriad other crucial life and performance functions.

We can’t run without ‘em. As such, each organ is surrounded by fascia, which helps connect and support those organs within our orthopedic–‘mechanical runner’–system. And since running is whole-body movement, our visceral organs must stay relatively stable yet also move to allow full arm, leg, and trunk motion for efficient running.

Does this seem a little ‘fringe’ to you? That’s understandable, until we stop to think about the real connections between viscera and our key orthopedic systems. For example:

  • The large intestine sits atop both hip flexors; and
  • The liver rests adjacent our diaphragm and ribcage.

Logically and mechanical speaking, these ‘guts’ gotta’ glide! And if you’re like me, you’ll be shocked at how common ‘sticky guts’ can be and the substantial impact this movement restriction can have on running mobility, strength, and efficiency.

What Guts You Have! The What and Wear

Here is a short list of important visceral organs and tissues that most significantly impact the running stride:

  • Diaphragm
  • Stomach
  • Small intestine
  • Large intestine
  • Liver
  • Bladder

For a nice three-dimensional visual, this video is a fantastic walk-through of the abdominal anatomy by Dr. Sam Webster, a senior lecturer in anatomy and embryology at Swansea University Medical School in the United Kingdom. He is also an ultrarunner!

While providing life-giving primary functions, these visceral organs and tissues must also acquiesce to the musculoskeletal system. They must allow for the subtle-but-vital motion necessary to generate optimal mobility in the running stride: sliding, gliding and even rolling within the trunk and pelvis, to the tune of three times per second.

So, why do they get stuck and what happens when they do?

Causes of Visceral-Mobility Loss

There are a number of threats to visceral mobility.


Generally speaking, not moving enough due to a sedentary (non-running) lifestyle is a risk factor in visceral range-of-motion loss. Prolonged sitting can cause aspects of the viscera to ‘stick,’ preventing elongation of the trunk.


Poor hydration, or periods of severe dehydration, can impair visceral mobility, which relies on adequate hydration to lubricate visceral fascia.

Direct or Indirect Trauma

Direct trauma includes any injury that causes actual tissue damage or deformation. This includes any punctures, lacerations, as well as surgical incisions. Such traumas create underlying scar tissue, or fibrous connective tissue produced by the body to quickly heal and ‘hold together’ damaged tissue. Scar tissue is a vital safety net that protects vulnerable injuries, but it is also stubborn, often outlasting the actual injury by months if not years. Fibrous scar tissue can significantly impair visceral mobility throughout the abdominal, pelvic, and ribcage areas. Major direct trauma can also create large amounts of chemically induced tissue adhesions.

Indirect trauma physically impacts the external system. They are blunt forces to the trunk, pelvis, or ribcage. Such traumas–commonly from falls or being struck by objects–seldom result in overt tissue damage, yet they can still result in visceral-mobility loss. A seemingly benign trail running stumble might easily be walked off in a few minutes, and result in a bit of soreness for a day or two. Yet such traumas can create inflammatory processes with longstanding consequences. The inflammatory cascade is a chemical response that stimulates tissue healing in the area of an injury. This response is often general and non-specific. Chemical residue from inflammation can result in tissue adhesions, or small-but-powerful chemical cross-linkage bonds between fascial tissues in the bruised area. Tissue adhesions, nearly as strong and seemingly just as stubborn as scar tissue, can abnormally bind organs to adjacent tissue fascia, restricting normal motion. Hence, ‘sticky guts!’


Any illness that significantly impacts the viscera–the gastrointestinal (GI) system, in particular–can result in similar tissue adhesions seen with acute and blunt-force trauma. Acute and chronic inflammatory GI conditions can cause systemic inflammation resulting in ‘sticky guts. Examples of acute conditions are food poisoning, viral infection, and bacterial/protozoan infections such as giardiasis. Examples of chronic conditions are irritable bowel syndrome, and food allergies or intolerances.

Visceral Mobility and Organ Function

Vital organ function is beyond the scope of this article. However, efficient organ function–including both gross mechanical and subtle chemical actions–requires full and healthy organ mobility. Healthy internal-organ function requires movement, too!

Visceral Mobility and the Running Stride

Generally speaking, the running stride can be broken up into two halves:

  • Right leg push-off: right hip extension, left hip flexion, right trunk elongation, left trunk rotation.
  • Left leg push-off: left hip extension, right hip flexion, left trunk elongation, right trunk rotation.

Base on those reciprocal movements, here are the key visceral structures that must have adequate mobility to allow a fully efficient running stride:

Running Movement Viscera that Needs to Move
Right leg push-off diaphragm; liver; cecum; ascending and transverse colon
Left leg push-off diaphragm; transverse; descending and sigmoid colon; stomach; spleen

Mobility loss to any one of those key visceral structures can throw a veritable monkey wrench in the workings of our stride. Some effects include:

  • Liver: impacts diaphragm mobility and extensibility; affecting breathing, core stability, and trunk motion
  • Large intestine: major impact on both hip (and pelvic) flexion and extension as well as trunk elongation

Treating Visceral Mobility

Now that you buy in that visceral mobility is important, stop. Take pause. Be careful. Unlike our other soft tissues, which are relatively benign and extremely resilient, the abdominal viscera are very sensitive, laden with blood vessels and nerves, and easily impacted by any physical manipulation. Assessing–let alone treating–visceral mobility requires great care and subtle forces to prevent aggravation and injury.

This is an area best left for skilled manual therapists, including physiotherapists, osteopaths, and massage therapists who have the training, skilled touch, and caution to skillfully treat this area without aggravating or possibly injuring these crucial organs.

That said, here are some signs that you might need a visceral-mobility assessment or treatment:

  1. History of trauma, illness, or severe dehydration. These conditions are a set-up for visceral-mobility dysfunctions.
  2. Persistent range-of-motion loss to the hips, spine, trunk, or arms. If you have persistent stiffness in an area of your body, despite diligent stretching and/or other manual work to the musculoskeletal system, visceral mobility may be the root issue.
  3. ‘Stiffness’ or an overt lack of extensibility to the abdomen. While haphazard poking and prodding is strongly discouraged–with fingers, let alone using any massage tool–gentle push-pulling of the abdomen is a good start to determine the general mobility of the viscera.

Here is a brief video talking about visceral mobility, as well as a demonstration of light, general assessment of the abdomen:

Case Study: Runner with Chronic Leg and Low-Back Pain

This is a client of mine who is experiencing chronic leg and low-back pain. The patient has a history of both injury and trauma. Most notably, before beginning running, she played American football, invariably suffering numerous blunt traumas in the process. I have been treating her for various issues over the past year with generally good improvement. Then, several months ago, she was involved in a serious motor vehicle accident, where she was side-impacted on the vehicle’s passenger side at highway speed.

She is nearly fully recovered and returned to running, but continues to have knee, hip, and, most notably, low-back pain.

This is a video comparison of her leg swing, which mimics the running-stride action. The video on the right is the ‘before’ motion. We then did a full treatment of her abdominal viscera, with special attention to her left side–stomach, small intestine, liver, descending and sigmoid colon–all of which were restricted around her left hip and pelvis. The left video is the ‘after’ treatment. No other ‘orthopedic’ intervention was performed:

This is one of the most dramatic before-and-after results I’ve seen in such a restricted leg-swing motion, and it’s all from a single visceral-mobility treatment. No other muscle, tendon, or joint stretching was required.


Visceral mobility–and in the grand scheme, fascial mobility–is hugely important for optimal function across multiple body systems. Subtle alternations to these tissue motions can have significant repercussions in the system and plainly affect how we put one foot in front of the other. As goal-oriented runners (and the folks who serve us), it behooves us to clue in on these new frontiers of health and wellness in pursuit of our best running selves!

Call for Comments (from Meghan)

  • Have you experienced mobility dysfunction in your viscera for which you’ve been treated? What was the experience like for you?
  • Based upon reading this article, do you think you might have an issue for which you could use treatment? What are your symptoms?
Joe Uhan

Joe Uhan is a physical therapist, coach, and ultrarunner in Auburn, California. He is a Minnesota native and has been a competitive runner for over 20 years. He has a Master’s Degree in Kinesiology, a Doctorate in Physical Therapy, and is a USATF Level II Certified Coach. Joe ran his first ultra at Autumn Leaves 50 Mile in October 2010, was 4th place at the 2015 USATF 100k Trail Championships (and 3rd in 2012), second at the 2014 Waldo 100k, and finished M9 at the 2012 Western States 100. Joe owns and operates Uhan Performance Physiotherapy in Eugene, Oregon, and offers online coaching and running analysis at