Metabolic Health 8 MIN READ

The interplay of glucose metabolism and breathing

Understanding blood glucose metabolism is important to comprehend the connection between breathing and glucose spikes. Blood sugar spikes are caused when a simple sugar known as glucose builds up in your bloodstream.

Written by Team Ultrahuman

Oct 09, 2022
Frame 8 min

Understanding blood glucose metabolism is important to comprehend the connection between breathing and glucose spikes. Blood sugar spikes are caused when a simple sugar known as glucose builds up in your bloodstream.

The food you eat is broken down into glucose. It is the key nutrient that powers our brain, muscles, and other organs. For glucose to be unlocked as a fuel, it needs to be inside our cells.

ULTRAHUMAN 12th AUG 0973 min


  • Blood sugar levels fluctuate all day long. Patterns of rises and crashes can offer valuable and actionable insights into your metabolic health,
  • The burning of fat is closely tied to insulin levels, which in turn depend on, or are closely related to, blood glucose,
  • A good first step is becoming aware of where your levels stand. Glucose monitoring can provide you with great insights such as glucose variability.

Breathing & Glucose Metabolism

Insulin, a hormone produced by your pancreas, unlocks cells so that glucose can enter them. Once it is granted entry into the cells, it is used by various enzymes or small proteins that expedite chemical reactions to transform glucose into different molecules. The aim of this cellular respiration process is to release the energy stored in the bonds of atoms that make up glucose.

Without insulin, the glucose keeps floating in your bloodstream with nowhere to go, becoming increasingly more concentrated over time. The pancreas then produces glucagon, a hormone that prompts the liver to release stored sugar or glycogen.

This interaction of glucagon and blood sugar ensures stable blood glucose levels in the body and the brain. The cells of individuals who have insulin resistance don’t respond well to insulin, barring glucose from entering them with ease.

The glucose level in their blood rises over time even as their body produces more insulin as the cells resolutely resist insulin. A lack of oxygen in the cells can trigger inflammation and insulin resistance. As oxygen concentration increases, the glucose concentration at which insulin is released becomes lower.

Breathing is defined as pulmonary ventilation – the movement of air between the atmosphere and the lung alveoli or the air sacs in lungs resembling balloons.

When air travels to the lungs, the process is called inspiration and when it moves out of the lungs, the action is termed expiration. The respiratory centre resides in the brain stem.

The thoracic cage, the diaphragm, and other muscles are also roped in during this course of ventilation.

Compared to other functions such as digestion or cardiovascular activity, breathing can be regulated voluntarily. The behavioural or voluntary control of breathing is located in the motor and premotor cortex of the brain.

It alludes to breathing with conscious control – a self-initiated change in breathing before vigorous exertion or effort. Conscious breathing is a broad term.

Essentially, it covers ways of breathing that induce an intentional awareness of our breathing patterns. Such awareness allows one to begin breathing in a conscious manner targeting any number of goals.

Ultrahuman Ring AIR_recovery image

Conscious breathing has applications in yoga, meditation, as well as other disciplines. From diaphragmatic breathing to the Wim Hoff method, breathwork can assume many patterns. You can read more about conscious breathing techniques in our blog deconstructing its science.

Glucose Metabolism and The Nervous System

The central nervous system is made up of the sympathetic nervous system and the parasympathetic nervous system. The former activates the fight-or-flight response and the latter is responsible for the relaxation response.

Sympathetic & Parasympathetic Nervous System
Cortisol is a hormone considered to be the body’s warning system. It regulates blood pressure, increases blood sugar, and dictates sleep-waking cycles as well as how our bodies use proteins, fats, & carbohydrates. It is tethered to the fight or flight response.

The stress response starts in the brain. In case of stress or perceived stress, the amygdala (area of the brain that contributes to emotional processing) decodes the sights and sounds and sends an SOS signal to the hypothalamus.

The amygdala interprets the images and sounds. When it perceives danger, it instantly sends a distress signal to the hypothalamus. The hypothalamus communicates with the body through the autonomic nervous system.

When you experience stress or sense danger (whether real or perceived), the sympathetic nervous system is mobilized. It stimulates the adrenal glands to set off the secretion of catecholamines (including adrenaline and noradrenaline).

This leads to a spike in heart rate, blood pressure, and breathing rate. Blood is pushed to the vital organs. These are evolutionary adaptations to increase the chance of survival in life-threatening situations. Adrenaline gears the body for the fight-or-flight response.

It causes a sharp, but short-lived, increase in insulin resistance. This ‘stress hormone’ can directly impact our glucose levels – by spiking the amount of circulating glucose. It floods the body with glucose to provide a prompt source of energy to fight or flee.

As the initial deluge of epinephrine subsides, the hypothalamus rouses the HPA axis, consisting of the hypothalamus, the pituitary gland, and the adrenal glands.

The HPA axis relies on a series of hormonal signals to moderate the sympathetic nervous system. If the brain continues to detect something threatening in the environment, the hypothalamus triggers the release of adrenocorticotropic hormone (ACTH).

It travels to the adrenal glands and incites them to release cortisol. The body thus continues to stay on high alert. It inhibits insulin to prevent the storage of glucose.

When the threat passes, cortisol levels drop to trigger the parasympathetic nervous system, which elicits the relaxation response.

With frequent increases in cortisol levels and subsequent glucose spikes, one can become more susceptible to metabolic syndrome.

Left unchecked or with frequent occurrences, a pattern of cortisol release can leave blood sugar & glucose levels at a dangerously uplifted baseline. The increase in glucose without adequate insulin to allow it to be processed by a cell as energy can contribute to obesity concentrated in the abdominal area, hypertension, dementia, type 2 diabetes, and depression.

However, a reduction of cortisol levels can steer the body back into using its parasympathetic nervous system. Research suggests that consciously altering the way you breathe transmits a signal to the brain.

This then invokes the parasympathetic branch of the nervous system, which can decelerate the heart rate and digestion and induce feelings of calm.

It can also regulate the sympathetic system, which controls the release of stress hormones like cortisol.

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Breathing Exercises & Glycemic Control

Breathing exercises can help regulate cortisol, by extension reducing stress, and glucose volatility, and can also minimize other ancillary effects.

Diaphragmatic or belly breathing has shown effects of a shrunken body mass index, lower waist-hip ratio, and post-meal glucose levels.

It is considered a suitable therapeutic tool to reduce oxidative stress or the desired balance between antioxidants and free radicals.

Oxidative stress is correlated with glycemic variability. Coherent breathing has been studied to demonstrate a reduction in anxiety as well as stress levels.

Fasting blood sugar and post-prandial blood sugar can be decreased when diaphragmatic breathing exercises are performed regularly.

Effects of Mouth Breathing on Metabolic Health

Mouth breathing syndrome (MBS) is marked by inhaling and exhaling mainly through the mouth and is considered to be an abnormal respiratory function. Allergies, nasal congestion, a deviated septum of the nose and some sleep disorders like sleep apnea can cause mouth breathing.

Dr. Steven Park, a surgeon with a speciality in sleep medicine, and the host of the podcast, “Breathe Better, Sleep Better, Live Better” says, “When you lie down the blood vessels inside your nose fill up with blood.”

He explains that the rush of blood causes swelling as well as constriction. If you can’t breathe easily through your nose, you’re likely to open your mouth for air. That triggers a positive feedback loop.”

Experts suggest that breathing through the mouth is not as efficient and effective as breathing through your nose.

When you breathe through the mouth at night it causes cell hypoxia (low oxygen) amping up Deiodinase 3 activity which is the enzyme that metabolizes T4 to reverse T3 and T3 to T2.

Thyroxine, also known as T4, is a type of thyroid hormone. This causes reduced levels of T3 reaching the nucleus of your cells and reduced cell metabolism. This can lead to a condition called cell or tissue hypothyroidism, despite normal thyroid gland function.

A study suggests that breathing selectively through either nostril could have a marked activating effect or relaxing effect on the sympathetic nervous system, lending credence to the practice of pranayama in Yoga.

This ties into the therapeutic implications of being able to change metabolism by changing the breathing pattern.

Research suggests that sleep-disordered breathing can be a risk factor for metabolic syndrome. Metabolic syndrome refers to a group of abnormalities in glucose and lipid metabolism, believed to result from insulin resistance and/or central obesity.

Sleep-disordered breathing (SDB) is marked by loud snoring, mouth breathing, sleep fragmentation, and sleep-associated intermittent hypoxemia. To know more about conscious breathing exercises check out the powerful Vinyasa flow yoga series on the Ultrahuman app.


Deep, slow, & intentional breathing can enhance our body’s functions. This includes a balance of increased glucose production by the liver as well as higher blood sugar levels, both of which may spike intense, stressful situations.

Conscious breathing improves insulin effectiveness as well, enabling cells to consume glucose as energy. It also prevents a concentration of glucose in the bloodstream, which can affect blood sugar levels, and become dangerous over a sustained period if left unmoderated.

With better oxygenation in the body, the absorption of nutrients is also increased. A well-oxygenated system leads to better metabolic health.

Disclaimer: The contents of this article are for general information and educational purposes only. It neither provides any medical advice nor intends to substitute professional medical opinion on the treatment, diagnosis, prevention or alleviation of any disease, disorder or disability. Always consult with your doctor or qualified healthcare professional about your health condition and/or concerns before undertaking a new healthcare regimen including making any dietary or lifestyle changes.


  1. Blood Sugar Spike: Causes, Symptoms, and What to Do
  2. Slow breathing improves blood sugar by reducing body’s endogenous production of glucose
  3. Pathogenetic Role of Cortisol in the Metabolic Syndrome: A Hypothesis | The Journal of Clinical Endocrinology & Metabolism | Oxford Academic (
  4. Mouth Breathing and Hypothyroid Symptoms? – Rejuvagen Center
  5. Breathing through a particular nostril can alter metabolism and autonomic activities

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