• Kacy Seynders, PT, DPT

Is the Core Important? Abs-olutely.

As a runner, you know that it’s important to have a strong “core” to reduce risk of injury, but do you know why?


The Webster dictionary defines core as “The central, innermost, or most essential part of anything”. Well, if that doesn’t imply some importance, then I don’t know what does! So, let’s take a few minutes to gain some understanding of what the core is, how it functions, and what this means for us as runners.


While many of us think of the 6 pack abs that graces the covers of fitness magazines, the core actually refers to muscles deeper within the cavity of the body. The muscles that make up the true “core” will vary depending on the source or school of thought, but in the Physical Therapy world we are typically referring to the diaphragm, pelvic floor, lumbar multifidi, and transverse abdominus. The reason for this is that these are the muscles that work together to maintain an appropriate pressure in the abdominal cavity and support movement. The rectus abdominis and obliques, which we traditionally think of as core muscles are what we call global movers, responsible for bigger movements of the trunk. These are important, too, but they cannot do their job efficiently without the work of the aforementioned stabilizing muscles.




Think of the difference between hanging from a pull up bar vs. a rope. It will be easier to hold on to the bar, because you aren’t having to constantly compensate for movement of the rope.


While there is nothing wrong with crunches, sit ups, leg lifts, etc. as core exercises, we need to make sure that the deeper muscles are functioning well first. Exercises like planks, bird dog, deadbugs, pallof press, etc. are all targeted at maintaining a stable and strong trunk while the rest of the body is moving. These are also seen as the “boring” exercises, because they usually don’t produce that good muscle “burn” that we’re used to. Since they are demanding on the neuromuscular system (the brain-muscle connection), you might find your brain getting tired before your muscles. It’s important to train that cognitive muscle as well, so that when the going gets tough at the end of a workout or race, you can still activate your stabilizing muscles and reduce risk of fatigue-induced injury.


In addition to preventing injury, a strong core can also improve performance by way of improved force generation from the arms and legs. Going back to our pull up bar vs. rope analogy, we can generate more force pulling from a bar than a rope.


Hopefully by now this is all making sense, but I think we would be remiss to dismiss a more in-depth conversation about the diaphragm. Proper breathing during activity, whether it’s core exercises or running, is crucial to regulate the intraabdominal pressure that lends stability to the trunk. A common pattern seen among the general population is upper chest breathing, which indicates that the diaphragm is not descending fully into the upper abdomen and the lungs are not filled evenly. The goal of diaphragmatic breathing is to fill the lungs circumferentially, so that there is expansion of the entire rib cage: front, back, and both sides. Practicing this with exercise and more controlled environments will allow you to incorporate this while running.


I have a fun, personal anecdote to demonstrate this concept: Last summer I started doing some strides again after a few of my runs each week. Most of the time, I would get a muscle spasm in my mid-back. just below my sports bra line. It seemed to happen whether I was well hydrated or not. So one day, I turned on my PT brain and focused on my breathing, not my running form, with the strides. It worked! No more spasms.


The core is abs-olutely important when it comes to staying injury free. We can teach you the right exercises for your specific need!


Keep Going, you got this!

Kacy Seynders, PT, DPT