Fun Facts and Health Hacks with Stefan and Zack

• Health Hack: Low level cardiovascular activity upon waking for 20-40 minutes to help optimize sleep-wake endocrine cycles and improve sleep quality and quantity (1). This improves cortisol release, helps decrease melatonin release in the morning (which will improve its release at night) without amplifying it so high that you fatigue.


• Fun Fact: Thinking about the planetary bodies and the sun, earth spins around its own axis and orbits around the sun in a circular fashion. The sun itself, and the planets orbiting it also move through space in a linear direction. This as a unit forms a spiralling motion of our solar system moving through place which when looked at in 2D forms a sine wave of cyclic rhythmicity.
What is a Rhythm and Why Do We Find Them in the Human Body

• A rhythm is a cyclical natural phenomenon
• The human body, and many other life forms in nature, have evolved to adapt to their external and internal environment. This is done through some level of sensory perception of movement, light, temperature, chemicals and many others. The fact that nature works through yearly, seasonally, monthly and daily rhythms has meant the life forms in nature would have to do the same to optimally survive.

Circadian Rhythm

• This rhythm is our 24h sleep-wake cycle
• Around 6 am, depending on the person, cortisol levels start to rise which increase our heart rate, blood pressure, and utilization of glycogen stores to increase blood sugar levels. The body also releases a hormone called vasoactive intestinal polypeptide which allows for more blood flow through vasodilation, increases skeletal muscle contractility, decreases smooth muscle contractility (helping with morning bowel movements) and helps increase blood glucose as well.
• Due to the photoreceptors in our eyes and skin, natural light in the morning via sunrise, and in the evening from sunset, will also promote circadian rhythm optimization. The light in the morning will enhance cortisol release and inhibit melatonin production to improve alertness and focus. This Inhibition of melatonin in the morning helps create a bigger surge later in the evening from the pineal gland (around 6pm) to improve sleep quantity and quality.
• Melatonin starts to be produced in greater amounts around 10 pm, which makes you feel tired and changes brain activity to allow for better neural recovery.
Endocrine Negative and Positive Feedback Loops

• A negative feedback loop is when the product of a reaction decreases the rate of reaction. For example, the product being cortisol in the HPA axis, will inhibit the hypothalamus in the cycle so it doesn't get excessively produced. If there is low cortisol, it will excite the Hypothalamus in the cycle to produce more. We can see how this will create rhythmic fluctuations
• A positive feedback loop is when the product of a reaction increases the rate of reaction. These are less prevalent in the body. For example, during childbirth, uterine contractions are excitatory to the hypothalamus and posterior pituitary gland to release oxytocin. Oxytocin then increases uterine contractions. This is hard to see how a rhythmic cycle is made, but at some point the organs involved in the axis will fatigue and there will be a large rest period (refractory period) where they cannot produce the hormones.

Neural Rhythms

• Neural activity is the product of exchange of ions (sodium and potassium) that are present and adjacent to the nerve cell. With a given magnitude of exchange, there will be enough depolarization to create an action potential leading to an impulse.
• Sir Bernard Cats gave a speech regarding the endplate action potential reaching 50 mv for a muscle twitch. He also found that there were random 0.5 mv impulses which did not create muscle twitches. Stefan believes this may be for keeping the ions close in proximity to their relative pumps to allow action potentials to occur more quickly when needed as well as avoid the ions dispersing to fair away from the membrane. Nature doesn't do anything without reason.

Circulatory Rhythms

• Venous and lymphatic drainage require movement of soft tissues to help facilitate their return to the heart and lungs.
• When we sleep there is not a lot of movement in terms of skeletal muscle taking place.
• Our nervous system coordinates with our sleep cycles to allow for oscillatory muscle contractions to then maintain oscillatory pressure changes in the circulatory system (2).

Cerebrospinal Fluid Rhythms

• Respiration influences the rhythm of our cerebrospinal fluid (CSF) drainage and supply (3,4,5).
• Nasal inhales may also influence our memory (6).

The Gait Cycle

• The gait cycle is also a rhythm. If you were to look at the centre of mass in a functional individual and watch them walk (in any plane of motion) you would see a sine wave.
• This mechanical rhythm is crucial for all aspects of health
• These rhythms coordinate with others. A study found that during running gait, the heart will shift its diastole phase to foot contact and its systole phase to flight phase to optimize preload and afterload (7).

Rhythms in Assessment and Treatment

• In assessment, seeing the interconnectedness of the body really shows how we must take a global look and not become fixated on symptomology. Symptoms are only effects through which the body is trying to coordinate and compensate a clinical or subclinical pathology. We must find the cause to then allow health to be facilitated by the body once more.
• Having rhythm and control when interfacing with the body allows the CNS to not have to anticipate as many dangerous motions to protect itself with muscle and sympathetic tone. Having a smooth rhythm when assessing and treating will allow practitioners to gather a better understanding of tissue preferences, restrictions and textures.
• This can also be applied to training athletes who are more cortically driven in there movements. Adding metronomes, rhythmic dynamic exercises, music, breathwork, external cueing over internal, all can allow the CNS to better interpret sensory information and drive down to much potential sympathetic tone.

Resources

1. Fairbrother K, Cartner B, Alley J, Curry C, Dickinson D, Morris D, Collier S. Effects of exercise timing on sleep architecture and nocturnal blood pressure in prehypertensives. Vasc Health Risk Manag. 2014;10:691-698 https://doi.org/10.2147/VHRM.S73688
2. 2. Burgess, C., Lai, D., Siegel, J., & Peever, J. (2008). An endogenous glutamatergic drive onto somatic motoneurons contributes to the stereotypical pattern of muscle tone across the sleep-wake cycle. The Journal of neuroscience : the official journal of the Society for Neuroscience, 28(18), 4649–4660. https://doi.org/10.1523/JNEUROSCI.0334-08.2008
3. Bordoni, B., Purgol, S., Bizzarri, A., Modica, M., & Morabito, B. (2018). The Influence of Breathing on the Central Nervous System. Cureus, 10(6), e2724. https://doi.org/10.7759/cureus.2724
4. Wszedybyl-Winklewska, M., Wolf, J., Swierblewska, E., Kunicka, K., Mazur, K., Gruszecki, M., Winklewski, P. J., Frydrychowski, A. F., Bieniaszewski, L., & Narkiewicz, K. (2017). Increased inspiratory resistance affects the dynamic relationship between blood pressure changes and subarachnoid space width oscillations. PloS one, 12(6), e0179503. https://doi.org/10.1371/journal.pone.0179503
5. Dreha-Kulaczewski, S., Joseph, A. A., Merboldt, K. D., Ludwig, H. C., Gärtner, J., & Frahm, J. (2015). Inspiration is the major regulator of human CSF flow. The Journal of neuroscience : the official journal of the Society for Neuroscience, 35(6), 2485–2491. https://doi.org/10.1523/JNEUROSCI.3246-14.2015
6. https://journals.physiology.org/doi/pdf/10.1152/jn.00200.2019
7. Constantini K, Stickford ASL, Bleich JL, Mannheimer PD, Levine BD, Chapman RF. Synchronizing Gait with Cardiac Cycle Phase Alters Heart Rate Response during Running. Med Sci Sports Exerc. 2018 May;50(5):1046-1053. doi: 10.1249/MSS.0000000000001515. PMID: 29240004; PMCID: PMC6023589.