Heart Rate Variability and Stress

How Healthy Are You? What Does Healthy Really Mean?

When we think about health, what comes to mind? Often, it’s about how well we sleep, how nutritious our meals are, or how active we are. But the truth is, many of us only consider our health when something goes wrong. The question is: do we always have to wait until it’s too late to take action?

The Role of the Autonomic Nervous System (ANS) in Wellness

At the core of our wellness lies the Autonomic Nervous System (ANS). It’s the deep wiring of our neurology, the control systems running in the background of our body. The ANS consists of two major branches:

  1. Sympathetic Nervous System (Fight or Flight)

  2. Parasympathetic Nervous System (Rest and Digest)

Our healthy, steady-state is the Parasympathetic state. Sympathetics are the alarm state. The tiger jumps out of the bush and you either kill it or climb a tree- and fast. This demands increased blood pressure, increased blood sugar, increased adrenaline and cortisol among other things. These changes should be brief and infrequent.

The role of Stress

If those sympathetic affects sound like the picture of stress, it’s because they are very closely related. Keeping your autonomics in check (Bio-Feedback, Tai Chi, Chi-Gong, Meditation) as well as maintaining a robust capacity for recuperation are the answers.
 
The idea that HRV could be an indicator of our wellness isn’t new. As early as 1733 (!) a difference in the beat-to-beat interval of a human heartbeat was identified (1). That’s what HRV is- a variation in the time from heartbeat to heartbeat. The observation is that a person who has little variation in the timing of their heartbeats is reflecting stress. As we have pointed out before, the real issue with stress isn’t the stressor, it’s the failed adaptation to the stressor. Failure to adapt. Well over 100 years agon, Hans Selye wrote on the General Adaptational Syndrome, delivering a landmark paper wherein he coined the term stress as we use it today. It’s my opinion that there is no coincidence that the disorders that we associate with stress are also associated with diminished HRV.

HRV and its Connection to Health Outcomes

My interest was piqued by a study (of which now there are many) (2) performed by Cardiologists which tracked the HRV of patients which had undergone care for coronary infarcts (heart attacks) and found a strong relationship between poor HRV and subsequent morbidity and mortality. Since then there has been observed associations between qualified HRV and several other disorders such as obesity (3) and mental health disorders (4). With these kinds of confirmation I find it to be clear that HRV measurement and interpretation are a worthwhile consideration in not only wellness regimens but management of pathology.

My Personal Experience with HRV

I personally began to explore HRV years ago, with the use of the EliteHRV with a polarbeat chest strap heart rate sensor. While the chest strap sensors remain the high-bar for HRV detection, it must be said that electronics have improved considerably over the years and devices which render the R-R interval as an average would still, over time, report increases and decreases in the HRV which would yield the real insight that we are talking about here. My interest was the glimpse into my own recovery state as I worked (I was in practice then) as well as trained and it turned out that my recovered state was not simply a reflection of the patterns of my training volume and intensity. Life and work were relevant and the time spent measuring the HRV deviations was very insightful, refining my intuitive skills. I feel that one of the great voids in western medicine is the blind spot we have for the entire concept of the human constitution- our recuperative wherewithal.

The Influence of Lifestyle on HRV

HRV is clearly affected by lifestyle. It is clearly associated with sleep and diet. Quality of sleep benefits from good sleep hygiene; logistical, dietary, emotional and mechanical. The diet is probably the real wide-open frontier as pertains to finding new means of improvement. Cellular wellness, optimized digestion and gut health, containment of oxidative stress (Selye was big on this) as well as visceral/organ strength and wellness are areas where many of us have room for improvement.

Exercise: Stress or Strength?

But how about exercise? Didn’t we say that stress was bad? Won’t exercise just stress us out more? Well, to be clear, exercise presents a paradox of sorts. Exercise, in it’s many forms, forces the expression of very important cellular machinery (like mitochondria) that are crucial to adaptational fettle. Being overtrained, however, is clearly contra to being strong, adapted and well. There is, for each of us, a “sweet spot” for exercise volume and intensity that we must each find for ourselves. And to keep it interesting, you should never forget that your sweet spot, your place of balance, is a constantly moving target.

Also important in the planning and execution of the exercise/training in your life is an awareness of overtraining at the tissue level. Our global wellbeing is no better than the sum of its parts. Overtrained/overwhelmed muscles, tendons and other structures start out a nagging issues but can combine or escalate to derail not just your training but your wellness.

Can getting adjusted help?

The most obvious way a Chiropractic adjustment would help we be as an upper cervical adjustment could affect vagal tone. Vagal tone speaks to the fullness (or lack thereof) of the Autonomic control being delivered through your Vagus Nerve, cranial nerve X (10) which has very wide ranging effects on health and wellness (5).

The old school chiropractors looked at health as a state of dis-ease, and they were on to something. Ask anyone that has had a good adjustment, there’s nothing like it.

 

[1] Hales, Stephen. “Stephen Hales (1733) and the Birth of Modern Physiology.” PubMed Central, National Library of Medicine, 2011, https://pmc.ncbi.nlm.nih.gov/articles/PMC3225923/#:~:text=Stephen%20Hales%20(1733)%20was%20the,health%20and%20disease%20has%20exploded.
[2]Tsuji, H., et al. “Variability of Heart Rate and Risk of Sudden Cardiac Death.” Journal of the American College of Cardiology, vol. 33, no. 4, 1999, pp. 1164-1169. JACC, https://www.jacc.org/doi/10.1016/S0735-1097%2899%2900468-4.
[3]Malik, M. et al. “Heart Rate Variability and Risk of Cardiac Events: The Role of Autonomic Nervous System.” PubMed Central, National Library of Medicine, 2020, https://pmc.ncbi.nlm.nih.gov/articles/PMC8072942/.
[4]Carvalho, Angelo A., et al. “Heart Rate Variability as a Prognostic Tool in Psychiatric Populations.” PubMed Central, National Library of Medicine, 2022, https://pmc.ncbi.nlm.nih.gov/articles/PMC10596135/#:~:text=Heart%20rate%20variability%20(HRV)%20is,prognostic%20tool%20in%20psychiatric%20populations.
“Stimulating the Vagus Nerve.” Cedars-Sinai, Cedars-Sinai Medical Center, 2021, https://www.cedars-sinai.org/blog/stimulating-the-vagus-nerve.html.

Written by: Donaid Seals D.C

Dr. Seals is a practicing Doctor of Chiropractic with over 25 years of experience caring for people across three states. His thinking is the product of his education, practice experience and many years in the natural foods and fitness industry. He has become living proof that old muscleheads don’t die-or fade away; sometimes they grow up to bring real-world expertise to the clinical picture. Traditional background information is available here.