Stress and the nervous system
The Parasympathetic Nervous System (PNS), also called the anabolic, or rest, repair and rebuild nervous system, is responsible for digestion, elimination, and regulating repair of the body. The PNS also stimulates immune function at night during sleep and PNS function is closely linked to the timing and release of many key immune hormones and specialized immune messengers.
The Sympathetic Nervous System (SNS) is often called the “fight or flight” nervous system because the SNS prepares the body to fight or to flee from danger. When the SNS becomes the dominant branch of the nervous system, blood is shunted away from the internal organs and into the muscles and periphery of the body to facilitate action. The SNS is also referred to as the catabolic nervous system because when it is active, there is increased utilization of many nutrients and hormones and also greater tissue destruction is generally taking place. It is important to realize that when the SNS is dominant, the functions of the PNS are proportionately shut down. If this happens too frequently, many vital SNS functions become labored and vital PNS functions are relatively inhibited.
Stress is, without a doubt, a major player in a variety of health problems—including pain, anxiety, depression, to cardiovascular disease to IBS or even Tinnitus. So what’s the best approach to combat the epidemic of chronic stress?
Here’s where Heart Rate Variability (HRV) comes into play. Heart rate variability (HRV) is the beat-to-beat change of the heart and a measure of the Autonomous Nervous System (ANS). The ANS has two main branches. The sympathetic nervous system that controls fight or flight. Think of this as the gas pedal in your car. It will speed up your heart rate or increase sweat. The parasympathetic nervous system is the brake. It helps you to rest and digest or feed and breed. It will slow down your heart rate. If you are hunting, for example, the sympathetic nervous system permits you to be attentive and focused. But when eating, you want to turn that off so that the nutrients can be absorbed. The parasympathetic nervous system helps you do that and also sleep, so you can recharge your batteries.
Imagine for a moment that instead of the PNS spending most of the time in the body’s driver’s seat, the SNS were running the show. Instead of a body in a generally relaxed state; digesting well, pumping blood via low pressure, with a heart rate that only speeds up when needed, you have a body existing in a perpetually hyper-aroused state. Always exhausted but never able to sleep. Heart racing, but unable to physically exert. Wanting to have an orgasm, but unable to become sexually aroused. Such is the nature of SYMPATHETIC DOMINANCE.
Most people in the West are too revved up. There is too much gas or sympathetic nervous system. It is part of the reason that we have trouble sleeping and stress-related health issues. It also explains digestive issues as the SNS is still active when we eat and digest.
A low HRV represents too much stress in the system. A high HRV, a flexibility of the nervous system and a potentially optimal response to stress. Our emotional state impacts HRV. HRV patterns shift with different emotions. Positive emotions show a smooth pattern in heart rate. Stress or frustration show a more choppy pattern.
Heart-focused breathing is essential in balancing and training a nervous system that that spends too much time in fight or flight. The more time we spend in a coherent, parasympathetic state, the more resilient we become.
The Heartmath Institute has done groundbreaking research on the intelligence of the heart, the importance of heart-focused breathing and offer a variety of devices to track the HRV. Heartmath video