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Can stress Cause hip Pain? Correlation with CO2 Tolerance

Breaking Down the Link: Can Stress Cause Hip Pain? Unraveling the Intriguing Connection.

breathing calves female runners hamstrings hip flexor rotation stacking Feb 14, 2024

It may sound far-fetched but if we look at the connection between stress, physiology, and biomechanics, feelings of stress and anxiety can be related to hip pain, neck pain, and back pain. So can stress cause Hip pain, long story short, Yes! But why? Discover how breathing, stress, and chronic tension are all connected!  

On Sunday I shared this video on my Instagram.

Essentially, I made my husband a guinea pig in our kitchen on Friday night to show what happens to your oxygen levels after a long breath hold.

Spoiler, they didn’t change at all. 

If his oxygen levels didn’t change, then why did he feel such a strong need to breathe (other than the fact that his “lungs felt like they were going to explode” as he put it)?


CO2 Tolerance: Breathing, Anxiety, Recovery and Performance:

Breathing is initiated by the brain, not to get more oxygen in, but to get rid of carbon dioxide! Exhalation drives the breathing process. What does this mean for your performance, recovery, and overall stress resilience? Most understand the basic idea that you breathe in oxygen and breathe out carbon dioxide (CO2). But did you know that CO2 is oxygen’s super helper?

We need CO2 around to actually use the oxygen we breathe in.

This system is tightly controlled by CO2 sensors in the brain stem. Periods of stress or over-breathing (either chronic or acute) can make this system hypersensitive to CO2. This means your body will initiate increased reparation BEFORE it’s really necessary. 

Sped-up respiration speeds up respiration.When this feedback loop goes unchecked, we are breathing in more oxygen without actually being able to use it. This is the opposite of what we want when we are talking about improving our performance and metrics like VO2 max.


When this feedback loop goes unchecked, our body interprets this as a stress response - anxiety. In a state of increased stress response, the body will struggle to recover from the work you are putting in with your workouts.

When this feedback loop goes unchecked, the body (and humans in the body) will likely become hypersensitive to all the things. " For me my first signal is noise, every little noise my kids make drives me up the wall."

That’s why CO2 tolerance is a skill we build in my Women’s Running Academy!

Improved CO2 tolerance means developing the tools you need to get out of that hyper-sensitive, over-breathing feedback loop. It means being able to take a minute to step back into your body and understand what it’s telling you.


Improved CO2 tolerance means more oxygen efficiency (improved performance). CO2 also plays a large role in our autonomic nervous system function. Improved CO2 tolerance means improved nervous system and stress resiliency (improved recovery).


Stress and Your Hip Pain (or neck, or back...):


Also, from a biomechanics perspective, often when CO2 tolerance is low it’s difficult to get a full exhale (that alarm goes off too early). This can make it difficult to find that stack I’m always talking about and connect with your deep abs.

And that stack affects more than just your abs.

Do any of these sound familiar?

  • Your low back is tight and sore after your run.
  • Your calves, hip flexors and/hamstrings are always tight no matter how much you stretch them.
  • You have neck tension that builds throughout a run and constantly feel like you need a massage.

What if I told you this ALL ties back to your breathing?


As show in the image above, all of these are connected:

  • Shallow breathing
  • Flared front lower ribs
  • Anterior pelvic tilt 
  • Compression in the back ribs
  • Compression in the low back
  • Poorly aligned (aka. not stacked) diaphragm and pelvic floor

When we look at how this plays into what you are feeling in your body we see:


This body needs:

1 - Learn to exhale fully and to breathe through the nose as often as possible. Here are some tips for improving your CO2 overall to make this possible.

2 - Learn to orient the pelvis using the proximal hamstrings, not by just squeezing the glutes and tucking under.

3 - Shift the center of mass back by creating an expansion in the ribcage on the back*. Think “stretch from the inside” with your breath.

*Many people (like me 2 years ago in that picture), will create compression on their front ribs too. Essentially crunching down to exhale from the outside instead of using the diaphragm on the inside. This person will need some "stretching from the inside" on the front and back ribs.

So many runners skip these steps and go right for the symptom… constantly feeling the need to stretch or get massages all while running more to deal with rising levels of anxiety. 

So many runners get stuck in the endless loop of injury and burnout. They continuously fall short of their goals because they are so focused on just doing the thing to move forward instead of taking the time to slow down and address the fundamentals.

In Women’s Running Academy, we start with these important foundations.

Do we still train hard, lift heavy, jump high, and run fast? Hell yeah!

We simply do it through this lens of understanding how the whole body is working together to accomplish the task AND how we can support the body toward executing that task more efficiently and effectively so that you can run faster, longer, and more freely.

Learn more about the Women’s Running Academy here.


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