How Is Your Diaphragm Function?

Your diaphragm is the most important muscle in your body, without it, the auxiliary breathing muscles have to figure out how to get enough oxygen into your systems.  The result? Your entire body has to adjust and compensate further.

Quick Anatomy Focus:

The diaphragm’s primary job is to create negative internal pressure in the thoracic cavity which then draws air into the lungs. There are other muscles that assist the diaphragm, and can also suck air into the lungs but they are not able to do the same job as effectively and more importantly when you initiate breathing from any other muscle than your diaphragm then your brain thinks that you are stressed.

  • The diaphragm is your primary breathing muscle and is supported by other breathing and skeletal muscles.
  • Accessory breathing muscles include: the external intercostals; the scalenes; and the sternocleidomastoid (SCM).
  • The diaphragm is a postural muscle.
  • It has a functional connection with your pelvic floor.


In fact, it takes twice as much effort to get the same tidal volume of oxygen into your lungs when you favour the accessory muscles over the diaphragm, and it really doesn’t make sense to your brain when you do this.

How Does Switching From Diaphragm Breath Affect My Well Being?

Your brain believes that you have switched from diaphragm breathing because you are not in a relaxed state. Not being in a relaxed state, according to your brain, means that you are to some degree stressed even if you think you are feeling ok about your day.

Your nervous system doesn’t think  it can only feel, so as it feels the accessory muscles ( intercostals, scalene’s, SCM ) taking over it responds accordingly, just as it was designed to.  In short the fight/flight process has begun.

The 1-2-3 of breathing.

Breathing has a correct muscle firing sequence just like the rest of your body so you must breathe in the following sequence for optimal health.

  1. Diaphragm.
  2. External intercostals.
  3. Scalene and SCM and a number of other skeletal muscles become involved.
Does Sitting Affect Your Diaphragm Function?

YES! Absolutely yes. In fact sitting decreases function by at least 1/3.

You actually don’t need full use of your diaphragm all the time but when you sit we have a tendency to slouch, this postural change is the real problem because slouching is also the posture of tiredness, stress, sadness etc.

The further forward you sit the less space your diaphragm has to to its job.

Are Breath Retention Exercises Helpful?

Breath retention exercises are important for retraining and strengthening the diaphragm but before you add complex breath techniques you must first train your diaphragm to work properly and the best way to do this is through diaphragmatic breathing exercises or belly breathing and here is a wonderful video from orthopedic surgeon and yogi, Ray Long.


Images: Ray Long – Key Muscles of Yoga.