UNDERSTANDING THE INFLUENCE OF POSTURE ON BREATH AND ENDURANCE PART ONE
The influence of posture on breath and cardiovascular performance is one of the most underappreciated factors in endurance training. In this article, we’ll take an in-depth look at how posture drives our breathing patterns, which in turn impacts our ability to delay fatigue during endurance activities.
Let’s start from the beginning.
The act of breathing—whereby oxygen is taken in and carbon dioxide expelled—is a movement pattern, regulated by the nervous system and carried out by the muscles—specifically by the diaphragm and deep abdominals.
Like any other movement pattern, the components of the respiratory process are susceptible to change in response to mechanical influences, like repetitive movements and sustained postures.
When posture is “normal,” our diaphragm is dome shaped—like the canopy of a parachute. When we breathe in, the diaphragm contracts down, flattening the dome and drawing air into your lungs. At the same time, your intercostal muscles lift and expand your rib cage to accommodate the inflow of new air.
This allows air to freely circulate around our body, provides stability to our spine and pelvis, and preserves a natural balance of oxygen coming into the system and carbon dioxide going out.
Conversely, when posture or position is abnormal or “dysfunctional” our ability to make this exchange is compromised.
Postural Influences of Endurance Sports
By nature, endurance activities like running and cycling involve highly repetitive movements that take place in a single plane of movement: forward. These patterns heavily recruit the hip flexors and quadriceps, which leads to a predictable pattern of overuse and overload.
Short, tight quadriceps and hip flexors act to pull the lower spine forward, increase anterior—forward—tilt of the pelvis, and push the rib cage up and forward.
This “over-extended” posture pulls the abdominals and hamstrings into a mechanically long position and flattens the diaphragm.
When the diaphragm loses dome height, it loses its mechanical advantage. When this happens it loses its ability to effectively pump air in and out of our lungs, and other muscles around the rib cage and neck have to compensate.
The brain and central nervous system interpret alterations in breathing dynamics as a threat to survival which, in turn, sets off a series of evolutionary fire alarms that kick our system into survival mode.
Our sympathetic nervous system—which regulates that fight or flight response—initiates a series of fail-safe reactions to buffer the threat. Those reactions include a spike in cortisol and adrenalin, muscle stiffening, increased heart rate and blood pressure. Heart rate variability, a measure of system adaptability, decreases.
When we are in this state of high sympathetic tone, there’s another major shift that occurs in our blood chemistry. The proportion of carbon dioxide in the blood relative to oxygen becomes skewed. This increases the relative acidity of the blood toward alkalinity, or basic.
In this environment, red blood cells hold on to their oxygen molecules rather than passing them off to mitochondria in working tissue. Without oxygen—the key ingredient in the production of aerobic energy—muscles have to progressively rely on shorter-lasting, anaerobic energy sources to continue fueling `movement.
While anaerobic metabolism is good for fueling immediate, short-term energy needs, it’s a limited resource. Keep moving long enough and eventually you hit critical mass, where the majority of energy being produced is anaerobic—this is known as the anaerobic threshold.
If you’ve ever sprinted flat out—legs shaking, lungs burning—then you know there’s a very small window of opportunity to continue moving once that threshold has been crossed.
So how do we prevent this burnout? In the next post, we will look at a few strategies to optimize breathing mechanics by reclaiming diaphragm position and restoring function to the muscles that become adaptively short and tight from running and cycling.
UNDERSTANDING THE INFLUENCE OF POSTURE AND BREATH AND ENDURANCE
The influence of posture on breath and cardiovascular performance is one of the most underappreciated factors in endurance training. In this article, we’ll take an in-depth look at how posture drives our breathing patterns, which in turn impacts our ability to delay fatigue during endurance activities.
Let’s start from the beginning.
The act of breathing—whereby oxygen is taken in and carbon dioxide expelled—is a movement pattern, regulated by the nervous system and carried out by the muscles—specifically by the diaphragm and deep abdominals.
Like any other movement pattern, the components of the respiratory process are susceptible to change in response to mechanical influences, like repetitive movements and sustained postures.
When posture is “normal,” our diaphragm is dome shaped—like the canopy of a parachute. When we breathe in, the diaphragm contracts down, flattening the dome and drawing air into your lungs. At the same time, your intercostal muscles lift and expand your rib cage to accommodate the inflow of new air.
This allows air to freely circulate around our body, provides stability to our spine and pelvis, and preserves a natural balance of oxygen coming into the system and carbon dioxide going out.
Conversely, when posture or position is abnormal or “dysfunctional” our ability to make this exchange is compromised.
Postural Influences of Endurance Sports
By nature, endurance activities like running and cycling involve highly repetitive movements that take place in a single plane of movement: forward. These patterns heavily recruit the hip flexors and quadriceps, which leads to a predictable pattern of overuse and overload.
Short, tight quadriceps and hip flexors act to pull the lower spine forward, increase anterior—forward—tilt of the pelvis, and push the rib cage up and forward.
This “over-extended” posture pulls the abdominals and hamstrings into a mechanically long position and flattens the diaphragm.
When the diaphragm loses dome height, it loses its mechanical advantage. When this happens it loses its ability to effectively pump air in and out of our lungs, and other muscles around the rib cage and neck have to compensate.
The brain and central nervous system interpret alterations in breathing dynamics as a threat to survival which, in turn, sets off a series of evolutionary fire alarms that kick our system into survival mode.
Our sympathetic nervous system—which regulates that fight or flight response—initiates a series of fail-safe reactions to buffer the threat. Those reactions include a spike in cortisol and adrenalin, muscle stiffening, increased heart rate and blood pressure. Heart rate variability, a measure of system adaptability, decreases.
When we are in this state of high sympathetic tone, there’s another major shift that occurs in our blood chemistry. The proportion of carbon dioxide in the blood relative to oxygen becomes skewed. This increases the relative acidity of the blood toward alkalinity, or basic.
In this environment, red blood cells hold on to their oxygen molecules rather than passing them off to mitochondria in working tissue. Without oxygen—the key ingredient in the production of aerobic energy—muscles have to progressively rely on shorter-lasting, anaerobic energy sources to continue fueling `movement.
While anaerobic metabolism is good for fueling immediate, short-term energy needs, it’s a limited resource. Keep moving long enough and eventually you hit critical mass, where the majority of energy being produced is anaerobic—this is known as the anaerobic threshold.
If you’ve ever sprinted flat out—legs shaking, lungs burning—then you know there’s a very small window of opportunity to continue moving once that threshold has been crossed.
So how do we prevent this burnout? In the next post, we will look at a few strategies to optimize breathing mechanics by reclaiming diaphragm position and restoring function to the muscles that become adaptively short and tight from running and cycling.