Stress levels and deep sleep

7494571 said:

I wouldn't mind seeing this thread re-vitalized with more contemporary understanding of what the body is doing and what the watch sensors are detecting. 

There is some reading available, although I do not know how much of it you already know. You can start with the following documents, and if you need more, there are many other documents in the Support section of Garmin's website, as well as at FirstBeat (the provider of the analysis algorithms for Garmin), and then there are countless of scientific papers on that topic in any academic database.

• What is Advanced Sleep Monitoring in Garmin Connect?
• How Does Body Battery Interact With Activity and Stress?
• Stress and relaxation during sleep and awake time, and their associations with free salivary cortisol after awakening.
• The Associations between Physiological Recovery Indicators during Sleep and Self-Reported Work Stressors
• New Research Reveals Vital Link Between Alcohol Intake and Sleep Quality Using Real-World Data
• Stress Awareness: What Is Stress and How Can You Manage It?
• Towards Better Sleep: What Do Hormones, Daylight and Being Active Have to Do with It?
• How to Get Good Quality Sleep: Your Questions Answered
• At the Heart of Stress and Recovery
• A Good Night’s Sleep, What Does It Mean?
• Is Your Sleep Restorative Enough?
• ...

trux Thank you for preparing that list of references, but they either tell me what I'd already heard (and incorporated into my sleep 'hygiene'), or they are of questionable relevance (one study is about people following a myocardial infarction).  My observation isn't so much about a particular shortcoming of Garmin/FirstBeat, but an appeal to the MDs/PhDs at FirstBeat to suggest how we take the watch's nightly "orange" stress measurements to a mainstream western medical practitioner for diagnosis.  I'd get additional blood work to supplement the watch's finding that there are frequent imbalances in my ANS if I knew what tests to get.  I'm not sure another polysomnography (sleep study) is going to show what the watch is detecting.

Not sure whether I understand what you are looking for. If you are really concerned about your sleeping patterns, and your generalist does not understand the correlation between HRV and stress and/or sleep apnea, then you better find a specialist. Conducting a polysomnography seems to be a reasonable idea, indeed.

Otherwise, as I wrote, there are countless scientific papers discussing the topics of HRV / stress and sleep disorders. Just google the terms and you'll get plenty of reading. Find the first few search hits below. However, I doubt you'll persuade your generalist to read them too.

• Correlation Analysis between Obstructive Sleep Apnea Syndrome (OSAS) and Heart Rate Variability 
• Changes in heart rate variability (HRV) in patients with severe and moderate obstructive sleep apnea before and after acute CPAP therapy during nocturnal polysomnography
• Correlation Analysis between Polysomnography Diagnostic Indices and Heart Rate Variability Parameters among Patients with Obstructive Sleep Apnea Hypopnea Syndrome
• Screening of Obstructive Sleep Apnea Syndrome by Heart Rate Variability Analysis
• Nocturnal heart rate variability may be useful for determining the efficacy of mandibular advancement devices for obstructive sleep apnea
• Nocturnal heart rate variability analysis as a screening tool for obstructive sleep apnea syndrome
• Screening of sleep apnea based on heart rate variability and long short-term memory
• ...

truxI think you helped me think this through a little better.   While Cardiologists were the original specialists who knew how to compute HRV (the old fashioned way), they were no more able to tell why a person had a particular number at a particular time than any other practitioner would be able to tell what was causing a person to have a high body temperature.  HRV is just a metric whose low values indicate further investigation is appropriate.  I contend there are no generalists or specialists who can tell the source of stress causing low HRV without additional tests of some kind.  Psychological/emotional stress can be a source, but an organ like the liver, pancreas, adrenals, kidneys, and on and on can cause the imbalance in the ANS that produces the observed HRVs.  Polysomnography may provide additional evidence of something wrong, but its not going to pinpoint the problem.  My concern is finding a generalist who will accept the fact that the watch's report of unusual stress is legitimately derived from low HRV, which indicates a trend of ANS imbalance worth determining the cause.   Thanks for the intellectual exercise.  Cheers.

I have only one coffee in the morning and no alcohol.  Usually still shows orange especially in the first part of sleep.  I can't work it out. 

1774595 said:

I have only one coffee in the morning and no alcohol.  Usually still shows orange especially in the first part of sleep.  I can't work it out.

Sounds to me that you are already stressed by looking at the graphs Relax, and your sleep may get better too. 

That would make sense if I was feeling stressed but that's not the case.  I do have some nights all in the blue but can't work out any difference to account for the change. I've had covid,  hoping it's the remnants of stress that are declining

I am not quite sure whether I understand what you are asking. Are you looking for a way to reduce the sleep stress? If so, then please have a look at the documents listed in my previous posts - there are many tips.

Or, are you rather asking why the watch detects high stress even if you do not feel any? If so, then it is also explained in the previously mentioned documents - stress (including sleep stress) is detected by measuring the HR Variability. There is a well documented and well understood relation between stress and the HRV, hence the detection is rather straightforward. Please read the documents for a detailed explanation.

Thanks for clarifying.  Yes,  im puzzled how and why my body is stressed despite me feeling relaxed.  I'm new to Garmin, I'd like to read the information you refer to. Can you tell me how I find it? Much appreciated